Filtration device, refining device, and production method for liquid medicine

ABSTRACT

A filtering device is for obtaining a chemical liquid by purifying a liquid to be purified, and the filtering device has an inlet portion, an outlet portion, a filter A, at least one filter B different from the filter A, and a flow path which includes the filter A and the filter B arranged in series and extends from the inlet portion to the outlet portion, in which the filter A has a porous base material made of polyfluorocarbon and a coating layer which is disposed to cover the porous base material and contains a resin having an adsorptive group.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of PCT International Application No.PCT/JP2019/007325 filed on Feb. 26, 2019, which claims priority under 35U.S.C § 119(a) to Japanese Patent Application No. 2018-055014 filed onMar. 22, 2018. Each of the above application(s) is hereby expresslyincorporated by reference, in its entirety, into the presentapplication.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a filtering device, a purificationdevice, and a method for manufacturing a chemical liquid.

2. Description of the Related Art

In a case where semiconductor devices are manufactured by a wiringforming process including photolithography, as a prewet solution, aresist solution (resist resin composition), a developer, a rinsingsolution, a peeling solution, a chemical mechanical polishing (CMP)slurry, a post-CMP washing solution or the like or as a diluted solutionof these, a chemical liquid containing water and/or an organic solventis used.

In recent years, as photolithography techniques have become advanced,patterns have been further miniaturized.

The chemical liquid used in such a wiring forming process is required tohave further improved defect inhibition performance. Generally, such achemical liquid is considered to be obtained by purifying a liquid to bepurified, which contains requisite components for the chemical liquid asmain components, by using a filter or the like so as to removeimpurities and the like.

As a filter that can be used for purifying such a chemical liquid,JP2017-002273A, JP2016-194040A, JP2016-194037A, JP2016-029146A, andJP2016-196625A describe a hydrophilic composite porous membraneincluding a porous fluoropolymer support and a predetermined coating.

SUMMARY OF THE INVENTION

The inventors of the present invention obtained a chemical liquid bypurifying a liquid to be purified by using the aforementioned filter andevaluated the defect inhibition performance of the chemical liquid. As aresult, the inventors have found that sometimes a sufficient defectinhibition performance is not obtained. Therefore, an object of thepresent invention is to provide a filtering device capable ofmanufacturing a chemical liquid having excellent defect inhibitionperformance. Another object of the present invention is to provide apurification device and a method for manufacturing a chemical liquid.

In order to achieve the aforementioned objects, the inventors of thepresent invention carried out intensive examinations. As a result, theinventors have found that the objects are achieved by the followingconstitution.

[1] A filtering device for obtaining a chemical liquid by purifying aliquid to be purified, the filtering device having an inlet portion, anoutlet portion, a filter A, at least one filter B different from thefilter A, and a flow path which includes the filter A and the filter Barranged in series and extends from the inlet portion to the outletportion, in which the filter A has a porous base material made ofpolyfluorocarbon and a coating layer which is disposed to cover theporous base material and contains a resin having an adsorptive group.

[2] The filtering device described in [1], in which the adsorptive groupis a group having at least one kind of group selected from the groupconsisting of an ether group, a hydroxyl group, a thioether group, athiol group, a quaternary ammonium group, a carboxylic acid group, and asulfonic acid group.

[3] The filtering device described in [1] or [2], in which the filter Bincludes at least one filter BU disposed on an upstream side of thefilter A on the flow path.

[4] The filtering device described in [3], in which the at least onefilter BU has a pore size larger than a pore size of the filter A.

[5] The filtering device described in [3] or [4], in which at least onefilter BU has a pore size equal to or greater than 20 nm.

[6] The filtering device described in any one of [3] to [5], in which atleast one filter BU contains a resin having an ion exchange group.

[7] The filtering device described in [6], in which the ion exchangegroup is at least one kind of group selected from the group consistingof an acid group, a base group, an amide group, and an imide group.

[8] The filtering device described in any one of [3] to [7], in which atleast one filter BU is different from the filter A in terms of material.

[9] The filtering device described in any one of [3] to [8], furtherhaving a return flow path capable of returning a liquid to be purifiedto an upstream side of a first reference filter from a downstream sideof the first reference filter, in which the first reference filterconsists of at least one kind of filter selected from the groupconsisting of the filter A and the filter BU.

[10] The filtering device described in any one of [1] to [9], in whichthe filter B includes at least a filter BD disposed on a downstream sideof the filter A on the flow path.

[11] The filtering device described in [10], in which at least onefilter BD has a pore size smaller than a pore size of the filter A.

[12] The filtering device described in [10] or [11], in which at leastone filter BD has a pore size equal to or smaller than 20 nm.

[13] The filtering device described in any one of [10] to [12], in whichthe filter BD contains at least one kind of compound selected from thegroup consisting of polyolefin, polyamide, polyfluorocarbon,polystyrene, polysulfone, and polyethersulfone.

[14] The filtering device described in any one of [10] to [13], in whichthe filter BD contains a second resin having a hydrophilic group.

[15] The filtering device described in any one of [10] to [14], furtherhaving a return flow path capable of returning a liquid to be purifiedto an upstream side of a second reference filter from a downstream sideof the second reference filter, in which the second reference filterconsists of at least one kind of filter selected from the groupconsisting of the filter A and the filter BD.

[16] The filtering device described in any one of [1] to [15], furtherhaving a tank arranged in series with the filter A on the flow path.

[17] The filtering device described in [16], further having a filter Chaving a pore size equal to or greater than 20 nm that is arranged inseries with the tank on an upstream side of the tank in the flow path.

[18] The filtering device described in any one of [1] to [17], in whichthe chemical liquid is at least one kind of chemical liquid selectedfrom the group consisting of a developer, a rinsing solution, a waferwashing solution, a line washing solution, a prewet solution, a waferrinsing solution, a resist solution, a solution for forming anunderlayer film, a solution for forming an overlayer film, and asolution for forming a hardcoat or at least one kind of chemical liquidselected from the group consisting of an aqueous developer, an aqueousrinsing solution, a peeling solution, a remover, an etching solution, anacidic washing solution, phosphoric acid, and a phosphoric acid-aqueoushydrogen peroxide mixture.

[19] The filtering device described in any one of [1] to [18], in whicha pH of the chemical liquid is 0 to 9.

[20] A purification device having the filtering device described in anyone of [1] to [19] and at least one distiller connected to the inletportion of the filtering device.

[21] The purification device described in [20], in which at least onedistiller includes a plurality of distillers connected in series.

[22] A method for manufacturing a chemical liquid that is for obtaininga chemical liquid by purifying a liquid to be purified, the methodhaving a filtration step of purifying the liquid to be purified by usingthe filtering device described in any one of [1] to [19] so as to obtaina chemical liquid.

[23] The method for manufacturing a chemical liquid described in [22],further having a filter washing step of washing the filter A and thefilter B before the filtration step.

[24] The method for manufacturing a chemical liquid described in [22] or[23], further having a device washing step of washing a liquid contactportion of the filtering device before the filtration step.

[25] A method for manufacturing a chemical liquid that is for obtaininga chemical liquid by purifying a liquid to be purified, the methodhaving filtering the liquid to be purified by using a filter A and afilter B different from the filter A so as to obtain a chemical liquid,in which the filter A includes a porous base material made ofpolyfluorocarbon and a coating layer which is disposed to cover theporous base material and contains a resin having an adsorptive group.

According to the present invention, it is possible to provide afiltering device capable of manufacturing a chemical liquid havingexcellent defect inhibition performance. Furthermore, the presentinvention can also provide a purification device and a method formanufacturing a chemical liquid.

In the present specification, “defect inhibition performance” of achemical liquid means the performance of the chemical liquid evaluatedby the method described in Examples. A chemical liquid used formanufacturing a semiconductor substrate is required to have “defectinhibition performance” corresponding to the type and role of thechemical liquid.

In the present specification, for a chemical liquid such as a prewetsolution, a developer, or a rinsing solution that is used for forming aresist film, the residue defect described in [Test Example 1] inExamples, which will be described later, is adopted as one of thetypical indices of defects in a lithography process, and the residuedefect inhibition performance is regarded as “defect inhibitionperformance”. Furthermore, for a resist resin composition containing aresin and used for forming a resist film, the bridge defect described in[Test Example 3] in Examples, which will be described later, is adoptedas one of the typical indices of defects derived from the resist resincomposition in a lithography process, and the bridge defect inhibitionperformance is regarded as “defect inhibition performance”. In addition,for a chemical liquid used as an etching solution, a resist peelingsolution, or the like, the particle defect described in [Test Example 2]in Examples, which will be described later, is adopted as one of thetypical indices of defects derived from the chemical liquid, and theparticle defect inhibition performance is regarded as “defect inhibitionperformance”.

Hereinafter, in a case where a characteristic is simply referred to as“defect inhibition performance”, this means the defect inhibitionperformance (residue defect inhibition performance, bridge defectinhibition performance, or particle defect inhibition performance)corresponding to the type of the chemical liquid.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view illustrating a filtering device according toa first embodiment of the present invention.

FIG. 2 is a schematic view illustrating a filtering device according toa second embodiment of the present invention.

FIG. 3 is a schematic view illustrating a modification example of thefiltering device according to the second embodiment of the presentinvention.

FIG. 4 is a schematic view illustrating a filtering device according toa third embodiment of the present invention.

FIG. 5 is a schematic view illustrating a modification example of thefiltering device according to the third embodiment of the presentinvention.

FIG. 6 is a schematic view illustrating a filtering device according toa fourth embodiment of the present invention.

FIG. 7 is a schematic view illustrating a filtering device according toa fifth embodiment of the present invention.

FIG. 8 is a schematic view illustrating a modification example of thefiltering device according to the fifth embodiment of the presentinvention.

FIG. 9 is a schematic view illustrating a filtering device according toa sixth embodiment of the present invention.

FIG. 10 is a schematic view illustrating a modification example of thefiltering device according to the sixth embodiment of the presentinvention.

FIG. 11 is a schematic view showing the relationship between the devicesin a case where a chemical liquid is manufactured using a distilledliquid to be purified that is purified in advance by a distiller.

FIG. 12 is a schematic view illustrating a purification device accordingto the first embodiment of the present invention.

FIG. 13 is a schematic view illustrating a purification device accordingto the second embodiment of the present invention.

FIG. 14 is a schematic view illustrating a purification device accordingto an embodiment of the present invention.

FIG. 15 is a schematic view illustrating a purification device accordingto an embodiment of the present invention.

FIG. 16 is a schematic view illustrating a purification device accordingto an embodiment of the present invention.

FIG. 17 is a schematic view illustrating a purification device accordingto an embodiment of the present invention.

FIG. 18 is a schematic view illustrating a purification device accordingto an embodiment of the present invention.

FIG. 19 is a schematic view illustrating a purification device accordingto an embodiment of the present invention.

FIG. 20 is a schematic view illustrating a filtering device according toan embodiment of the present invention.

FIG. 21 is a schematic view illustrating a filtering device according toan embodiment of the present invention.

FIG. 22 is a schematic view illustrating a filtering device according toan embodiment of the present invention.

FIG. 23 is a schematic view illustrating a filtering device according toan embodiment of the present invention.

FIG. 24 is a schematic view illustrating a purification device accordingto a conventional technique.

FIG. 25 is a schematic view illustrating a filtering device according toa conventional technique.

FIG. 26 is a schematic view illustrating a filtering device according toan embodiment of the present invention.

FIG. 27 is a schematic view illustrating a filtering device according toan embodiment of the present invention.

FIG. 28 is a schematic view illustrating a filtering device according toan embodiment of the present invention.

FIG. 29 is a schematic view illustrating a purification device accordingto an embodiment of the present invention.

FIG. 30 is a schematic view illustrating a filtering device according toan embodiment of the present invention.

FIG. 31 is a schematic view illustrating a purification device accordingto an embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, the present invention will be specifically described.

The following constituents will be described based on typicalembodiments of the present invention in some cases, but the presentinvention is not limited to the embodiments.

In the present specification, a range of numerical values describedusing “to” means a range including the numerical values described beforeand after “to” as a lower limit and an upper limit respectively.

[Filtering Device]

The filtering device according to an embodiment of the present inventionhas an inlet portion, an outlet portion, a filter A, at least one filterB different from the filter A, and a flow path (path through which aliquid to be purified flows) which includes the filter A and the filterB arranged in series and extends from the inlet portion to the outletportion (in other words, the filtering device has a flow path whichincludes a filter A and at least one filter B different from the filterA arranged in series between an inlet portion and an outlet portion andextends from the inlet portion to the outlet portion), in which thefilter A has a porous base material made of polyfluorocarbon and acoating layer that is disposed to cover at least a portion of the basematerial and contains a first resin having an adsorptive group.

Generally, as impurities in a chemical liquid involved in the defectinhibition performance of the chemical liquid, for example, a gel-likeorganic compound (particularly, a polymer compound) component, inorganicfine particles, inorganic ions, and the like are considered.

It is considered that among these, the gel-like polymer compound or theinorganic fine particles that can be solid contents in the chemicalliquid may be easily removed by a sieving effect of a filter, and thusthe defect inhibition performance of the obtained chemical liquid may beimproved.

In contrast, it is considered that the inorganic components other thanparticles and the ionic components may be easily removed by anadsorption function of a filter (such as the adsorption by theinteraction between ions and the adsorption by the hydrophilic andhydrophobic interaction), and thus the defect inhibition performance ofthe obtained chemical liquid may be improved.

By the inventors of the present invention, it has been found, for thefirst time, that in a case where a filter having a sieving effect and afilter having an adsorption effect are arranged in series on a flow pathof a filtering device, a chemical liquid is obtained which has a defectinhibition performance improved further than in a case where the each ofthe above filters is used singly. According to the inventors of thepresent invention, the mechanism yielding the above result is assumed tobe as below.

According to the study of the inventors of the present invention, it hasbeen revealed that sometimes defects occur in a case where microgel(containing an organic compound) which is not a source of defect aloneinteracts with inorganic fine particles and/or inorganic ions, in a casewhere inorganic fine particles, trace metals, and the like which are nota source of defect alone interact with a gel-like organic compound, orin a case where microgel interacts with inorganic fine particles, tracemetals, and the like.

Particularly, by the filtration based on a molecular sieving effect,microgel is not thoroughly removed due to the influence of solvation ina chemical liquid. In a case where the chemical liquid is applied to awafer and then dried, the effect of solvation is reduced, and thus gelis formed, which is considered as one of the causes of the occurrence ofdefects.

For such a complex source of defect, it is effective to remove each ofthe causative components interacting with each other. It is consideredthat in a case where the microgel component and the inorganic ultrafineparticle component and the inorganic ion component capable ofinteracting with the microgel component are removed by the sievingeffect and the adsorption effect, defects could be further reduced.

The filtering device according to the present embodiment has a sievingeffect brought about by the porous polyfluorocarbon (for example,polytetrafluoroethylene: PTFE membrane) coated with the resin having anadsorptive group and an effect of removing an ion source and/orinorganic fine particles brought about by the filter to be combined withthe porous polyfluorocarbon. Presumably, by the interaction of thefilters combined as above, the substances easily causing defects couldbe efficiently removed from the liquid to be purified, and thus thedefect reduction effect in the chemical liquid could be furtherimproved.

Hereinafter, the filtering device will be described using drawings. Inthe filtering device according to the embodiment of the presentinvention, because the filter A and the filter B are arranged in serieson the flow path, the liquid to be purified is sequentially filteredthrough the filter A and the filter B (or the filter B and the filterA). Hereinafter, a filtering device according to an embodiment of thepresent invention will be described. In the following section, afiltering device for a dead-end filtration method that filters theentirety of a liquid to be purified introduced into a filter by usingthe filter will be described for example. However, the filtering deviceaccording to the embodiment of the present invention is not limitedthereto, and may be a filtering device for a cross-flow method thatdivides the introduced liquid to be purified into a liquid to bepurified having undergone purification and a concentrate (sometimes theconcentrate is introduced again into a filter as a liquid to bepurified) or may be a filtering device for a method as a combination ofthe dead-end filtration method and the cross-flow method.

First Embodiment

FIG. 1 is a schematic view illustrating a filtering device according toa first embodiment of the present invention.

A filtering device 100 is a filtering device in which a filter 103 as afilter A and a filter 104 (corresponding to a filter BU) different fromthe filter 103 are arranged in series through a piping 105 between aninlet portion 101 and an outlet portion 102.

The inlet portion 101, the filter 104, the piping 105, the filter 103,and the outlet portion 102 are constituted such that a liquid to bepurified can flow in the interior of each of these members. Thesemembers are connected to one another and form a flow path S1 (paththrough which the liquid to be purified flows).

The shape of the inlet portion 101 and the outlet portion 102 is notparticularly limited as long as the liquid to be purified can beintroduced into and discharged from the filtering device. Typically,examples thereof include a hollow cylindrical piping (inlet portion andoutlet portion) having an inlet port and an outlet port. Hereinafter, anembodiment in which each of the outlet portion and the inlet portion isa piping will be described for example.

The shapes of the inlet portion 101, the piping 105, and the outletportion 102 are not particularly limited. Typically, examples thereofinclude a hollow cylinder shape in which the liquid to be purified canflow in these members. Although the material of these is notparticularly limited, it is preferable that a liquid contact portion (aportion that is likely to contact the liquid to be purified in a casewhere the liquid to be purified is filtered) thereof is formed of ananticorrosive material which will be described later.

The liquid to be purified introduced from the inlet portion 101 of thefiltering device 100 flows in the filtering device 100 along the flowpath S1. In the meantime, the liquid to be purified is sequentiallyfiltered through the filter 104 (filter BU) and the filter 103 (filterA) and then discharged out of the filtering device 100 from the outletportion 102. The form of the liquid to be purified will be describedlater.

For the purpose of allowing the liquid to be purified to flow, thefiltering device 100 may have a pump, a damper, a valve, and the like,which are not shown in the drawing, on the flow path S1 (for example, inthe inlet portion 101, the piping 105, the outlet portion 102, and thelike).

The shape of the filter 103 (filter A) and the filter 104 (filter BU) isnot particularly limited. For example, the filter A and the filter Bhave a flat shape, a pleated shape, a spiral shape, a hollow cylindricalshape, and the like. Particularly, in view of further improvinghandleability, typically, the filter A and the filter B are preferablyin the form of a cartridge filter having a core, which is formed of amaterial permeable to the liquid to be purified and/or has a structurepermeable to the liquid to be purified, and a filter which is disposedon the core in a state of being wound around the core. In this case,although the material of the core is not particularly limited, it ispreferable that the core is formed of the anticorrosive material whichwill be described later.

The method of arranging the filters is not particularly limited.Typically, it is preferable to arrange the filters in a housing notshown in the drawing that has at least one entrance, at least one exit,and at least one flow path formed between the entrance and the exit. Inthis case, the filters are arranged to cross the flow path in thehousing. The flow path formed in the housing forms a portion of the flowpath S1. While flowing through the flow path S1, the liquid to bepurified is filtered through the filters that are arranged to cross theflow path S1.

The material of the housing is not particularly limited. Examplesthereof include any appropriate hard and impermeable materials includingimpermeable thermoplastic materials compatible with the liquid to bepurified. For example, the housing can be prepared from a metal such asstainless steel or a polymer. In an embodiment, the housing is a polymersuch as polyacrylate, polypropylene, polystyrene, or polycarbonate.

Furthermore, in view of obtaining a filtering device having furtherimproved effects of the present invention, at least a portion of aliquid contact portion of the housing, which is preferably 90% and morepreferably 99% of the surface area of the liquid contact portion, ispreferably formed of the anticorrosive material which will be describedlater. In the present specification, the liquid contact portion means aportion which is likely to contact the liquid to be purified (here, thefilter is not included in the liquid contact portion), and means theinner wall of a unit such as the housing and the like.

<Filter A>

The filter A has a porous base material made of polyfluorocarbon and acoating layer which is disposed to cover the porous base material andcontains a resin having an adsorptive group. It is preferable that theentirety of the surface of the porous base material is coated with thecoating layer. However, the surface of the porous base material may havea portion as a region that is not covered with the coating layer. Thesurface also includes the surface of pores of the porous base material.

As the porous base material made of polyfluorocarbon, known porous basematerials can be used without particular limitation.

Examples of the polyfluorocarbon include polytetrafluoroethylene,perfluoroalkoxyalkane, a perfluoroethylene propene copolymer, anethylene/tetrafluoroethylene copolymer, anethylene-chlorotrifluoroethylene copolymer, polychlorotrifluoroethylene,polyvinylidene fluoride, polyvinyl fluoride, and the like. Among these,polytetrafluoroethylene (PTFE) is preferable. As the filter A, thosecommercially available as porous base materials made of PTFE can be usedas appropriate.

The pore size of the filter A is not particularly limited. Generally,the pore size of the filter A is preferably 0.1 to 50 nm, and morepreferably 0.1 to 20 nm.

In the present specification, “pore size” means a pore size determinedby the bubble point of isopropanol (IPA) or HFE-7200 (“NOVEC 7200”,manufactured by 3M, hydrofluoroether, C4F9OC2H5).

The method for manufacturing the filter A is not particularly limited.Typically, it is preferable to use a method of bringing the porous basematerial made of polyfluorocarbon (for example, PTFE) into contact witha composition for forming a coating layer containing a resin having anadsorptive group (for example, by means of coating and/or spraying) suchthat the coating layer is formed on the surface of the porous basematerial (including the inner surface of pores).

The coating layer contains a resin having an adsorptive group. As theresin, known resins can be used without particular limitation. Theadsorptive group is not particularly limited, and examples thereofinclude an ether group, a hydroxyl group, a thioether group, a thiolgroup, a quaternary ammonium group (quaternary ammonium salt group), acarboxylic acid group, a sulfonic acid group, a phosphoric acid group, asulfonium group, a diester group, a group having these, and the like.Among these, in view of further improving the effects of the presentinvention, a group is preferable which has at least one kind of groupselected from the group consisting of an ether group, a hydroxyl group,a thioether group, a thiol group, a quaternary ammonium group, acarboxylic acid group, and a sulfonic acid group. Particularly, a groupis preferable which has a thioether group and at least one kind of groupselected from the group consisting of an ether group, a hydroxyl group,a thiol group, a quaternary ammonium group, a carboxylic acid group, anda sulfonic acid group.

The resin may have one kind of adsorptive group or two or more kinds ofadsorptive groups.

The adsorptive group is not particularly limited, but is more preferablya group represented by *—S-L(R¹)_(m)(R²)_(n-m-1). In the above formula,L is an n-valent linking group (n is an integer equal to or greater than2), R¹ is at least one kind of group selected from the group consistingof a hydroxyl group, a thiol group, a quaternary ammonium group, acarboxylic acid group and a sulfonic acid group, and R² represents ahydrogen atom or a monovalent organic group. Furthermore, * represents abinding position, and m represents an integer equal to or greater than 0and equal to or smaller than n−1.

First Embodiment of Filter A

Examples of a first embodiment of the filter A include a filter having aporous base material made of polyfluorocarbon (typically,polytetrafluoroethylene, hereinafter, described aspolytetrafluoroethylene) and a coating layer which is disposed to coverat least a portion of the porous base material and contains at least onekind of copolymer selected from the following copolymer (I) andcopolymer (II).

The copolymer represented by Formula (I) or (II) is a random copolymeror a block copolymer. Rf is a perfluoro substituent, Rh is an adsorptivegroup, Ra is a methyl or ethyl group, m and n are preferablyindependently 10 to 1000, X is an alkyl group, and Y is a reactivefunctional group. In the coating layer, each of the copolymers may becrosslinked.

n and m represent a degree of polymerization of each repeating unit(hereinafter also referred to as “unit”). n and m preferably eachindependently represent 10 to 1000, more preferably each independentlyrepresent 50 to 400.

The content (based on mass) of the monomer block in the block copolymeris not particularly limited. For example, the content ratio of the twokinds of polymer blocks can be 99:1 to 50:50 (all expressed as “% bymass”). The polymer blocks can be present in the block copolymerpreferably at a content ratio of 90:10 to 70:30, and more preferably ata content ratio of 75:25 to 60:40.

The molecular weight of the copolymer is not particularly limited.However, the number-average molecular weight or the weight-averagemolecular weight (Mn or Mw) of the copolymer is preferably 10,000 to1,000,000, more preferably 20,000 to 200,000, and even more preferably40,000 to 100,000.

The reactive substituent represented by Y is preferably at least onekind of substituent selected from the group consisting of an aminogroup, a hydroxyl group, an acryloyl group, and a methacryloyl group.The copolymer may have two or more kinds of reactive substituents.

The perfluoro substituent represented by Rf is preferably aperfluoro-substituted alkyl group or a perfluoro-substituted alkylchain, and the alkyl chain may have one or more oxygen atoms in themolecular chain thereof. For example, Rf is preferablyC_(p)F_(2p+1)—(CH₂)_(q)(OCH₂)_(r). In the formula, p is 1 to 12, q is 0to 3, and r is 0 to 2. More specifically, examples of Rf in Formula (I)include CF₁₇CH₂, C₆F₁₃(CH₂)₂OCH₂, C₄F₉CH₂, CF₃, and the like.

In addition, examples of Rf in formula (II) includeC_(p)F_(2p+1)—CH₂CH₂, C_(p)F_(2p+1)—CH₂OCH₂, and the like. Morespecifically, examples thereof include C₈F₁₇CH₂, C₆F₁₃(CH₂)₂OCH₂, andthe like. Furthermore, Rf in Formula (II) may be C₈F₁₇CH₂CH₂.

Examples of the adsorptive group represented by Rh include a hydroxylgroup, an oxyalkylene group, a chlorine atom, an allyloxy group, analkylthio group, an alkylthiopropyloxy group, a group having these, andthe like. Among these, a hydroxyl group, a chlorine atom, an allyloxygroup, an alkylthio group, an alkylthiopropyloxy group, or a grouphaving these is preferable. The alkyl portion of the alkoxy group,alkylthio group, and alkylthiopropyloxy group may be substituted with ahydroxyl group, a carboxylic acid group, a sulfonic acid group, aphosphonic acid group, a quaternary ammonium group, an alkylsulfonegroup and/or a heterocyclic group.

In the copolymer represented by Formula (II), Ra is preferably a methylgroup.

Furthermore, X is preferably a methyl group.

Y may be an adsorptive group. As the adsorptive group, for example, atertiary amino group or a quaternary ammonium group such as apiperidinyl group, a pyridinium group, a dimethylamino group, or adiethylamino group is preferable.

The random copolymer represented by Formula (I) can be prepared by amethod including cationic ring-opening polymerization of a substitutedepoxide mixture. For example, a mixture of epoxide monomers havingappropriate substituents can be polymerized using an initiator saltincluding trialkylaluminum, a halogen anion, and an organic cation as acounterion. The organic cation in a salt including the organic cation asa counter cation is preferably an ammonium ion or a phosphonium ion suchas a bis(triarylphosphoranylidene)ammonium ion, abis(trialkylphosphoranylidene)ammonium ion, and atriarylalkylphosphonium ion. These are described in, for example, USPatent Application Publication No. 2009/0030175A1. Examples of thetriarylalkylphosphonium ion include [MePPh₃]⁺, where Me is methyl.Therefore, a mixture of each monomer, a perfluoroalkylepoxy monomer, andt-butylglycidyl ether (TBGE) can be polymerized as described below, andthe obtained copolymer is further reacted with an acid such astrifluoroacetic acid so as to remove a pendant t-butyl group.

The block copolymer represented by Formula (I) can be prepared by amethod including the sequential polymerization of an epoxide monomerhaving the Rf substituent and the subsequent ring-opening polymerizationof another epoxide monomer having an appropriate substituent such as analkyl group. Accordingly, for example, in a first step, a homopolymer ofa first monomer, which is an epoxide substituted with the Rf group, canbe generated, a second monomer having a substituted epoxide such as TBGEcan be added thereto, and in this way, polymerization is continued untila block copolymer is obtained.

The random copolymer represented by Formula (II) can be prepared by amethod including the cationic ring-opening polymerization of a mixtureof two 2-substituted 2-oxazoline monomers consisting of one monomerhaving the Rf substituent at the 2-position and another monomer havingthe Ra substituent at the 2-position.

As will be described below, the block copolymer represented by Formula(II) can be prepared by a method including the sequential cationicring-opening polymerization of an oxazoline monomer having the Rasubstituent such as 2-methyl-2-oxazoline and the subsequent cationicring-opening polymerization of another oxazoline monomer having the Rfsubstituent such as PF8Et-oxazoline (PF8Et is C₈F₁₇CH₂CH₂).

Furthermore, the block copolymer represented by Formula (II) can beprepared by a method including the sequential cationic ring-openingpolymerization of a 2-oxazoline monomer having the Rf substituent at the2-position and the subsequent cationic ring-opening polymerization ofanother 2-oxazoline monomer having the Ra substituent at the 2-position.

As will be described below, the 2-oxazoline monomer having the Rfsubstituent can be prepared by the reaction between3-perfluoroalkyl-propionic acid and ethanolamine or by the reactionbetween 3-perfluoroalkyl-propionitrile and ethanolamine.

The monomer is polymerized using, for example, a solvent which isgenerally used for carrying out cationic ring-opening polymerization orthe like. As the solvent, for example, aromatic hydrocarbons such asbenzene, toluene, and xylene, aliphatic hydrocarbons such as n-pentane,hexane, and heptane, alicyclic hydrocarbons such as cyclohexane,halogenated hydrocarbons such as dichloromethane, dichloroethane,dichloroethylene, tetrachloroethane, chlorobenzene, dichlorobenzene, andtrichlorobenzene, and mixtures of these are suitable.

The concentration of the monomer is preferably in the range of 1% to 50%by mass, more preferably 2% to 45% by mass, and even more preferably 3%to 40% by mass.

The polymerization temperature is not particularly limited, but ispreferably −20° C. to 100° C. and more preferably 20° C. to 100° C.

The polymerization reaction time is not particularly limited, but ispreferably 1 minute to 100 hours for example.

The polymer can be isolated by a suitable technique, for example,non-solvent precipitation or concentration of an appropriately quenchedreaction mixture.

The characteristics of copolymer, such as molecular weight and molecularweight distribution, can be determined by any of known techniques. Forexample, multiangle light scattering detector (MALS)-Gel PermeationChromatography (GPC) technique can be used. By the MALS-GPC technique, apolymer solution is eluted through a group of columns filled with astationary phase by using a mobile phase and a high-pressure pump. Bythe stationary phase, the polymer sample is separated by the size ofmolecular chain. Then, by three different detectors, the polymers aredetected. It is possible to use detectors arranged in series. Forexample, it is possible to use an ultraviolet detector (UV detector), amultiangle laser light scattering detector (MALS detector), and adifferential refractive index detector (RI detector) arranged in a linein this order. The absorption of light into the polymer at a wavelengthof 254 nm is measured by the UV detector, and the light scattered fromthe polymer chain relative to the mobile phase is measured by the MALSdetector.

In addition, based on the typical method known to those skilled in therelated art, the copolymer can be further modified by causing athiol-ene reaction between the pendant allyl portion and a hydrophilicthiol (for example, thioglycerol or mercaptoacetic acid).

Furthermore, based on the typical method known to those skilled in therelated art, which is described in European Polymer Journal vol. 43(2007) 4516, the copolymer can be further modified by causing anucleophilic substitution reaction between the pendant chloromethylportion and a hydrophilic thiol (for example, thioglycerol ormercaptoacetic acid).

The copolymer can be further modified such that the copolymer includes acrosslinkable reactive functional group represented by Y For example, byconverting one or more hydroxyl groups into an ester group usingacryloyl chloride or methacryloyl chloride, an acrylate copolymer or amethacrylate copolymer can be obtained. Alternatively, by bonding anamino acid to one or more hydroxyl groups, aminoester functional groupcan be obtained.

Method of Preparing Filter A (First Embodiment)

Next, typical examples of a method of preparing the filter A having theaforementioned coating layer will be described. For example, in themethod of preparing the filter A, the following steps are performed inorder.

-   -   Step of preparing porous base material made of        polytetrafluoroethylene    -   A step of coating the Porous base material with a solution        containing a solvent and the copolymer represented by        Formula (I) or Formula (II) so as to obtain a porous base        material with a coating layer.

The copolymer represented by Formula (I) or (II) is a random copolymeror a block copolymer, Rf is a perfluoro substituent, Rh is an adsorptivegroup, Ra is a methyl or ethyl group, m and n are preferablyindependently 10 to 1000, X is an alkyl group, and Y is a reactivefunctional group.

-   -   A step of drying the porous base material with a coating layer        so as to remove at least a portion of the solvent from the        coating layer including the solvent and the copolymer.

Furthermore, the preparation method may have the following step.

-   -   A step of crosslinking the copolymer present in the coating        layer

In a case where Y has an acrylate functional group or a methacrylatefunctional group, for example, crosslinks can be formed using aphotoinitiator or high-energy radiation such as ultraviolet. It isconsidered that the crosslinks will result in an extremely stablepolymer network structure for the coating layer.

Examples of the photoinitiator include camphorquinone, benzophenone,benzophenone derivatives, acetophenone, acetophenone derivatives,phosphine oxide and derivatives thereof, benzoin alkyl ether, benzylketal, phenylglyoxal ester and derivatives thereof, dimericphenylglyoxal ester, perester, halomethyltriazine,hexaarylbisimidazole/coinitiator-based photoinitiator, ferroceniumcompounds, titanocene, and combinations of these.

The coating layer is formed, for example, by the following method. Forexample, a porous base material made of polytetrafluoroethylene (PTFE)is preliminarily wet with an isopropanol (IPA) solvent and immersed in acoating polymer solution having a concentration in a range of 0.1% to10% by mass such that the porous base material is coated at roomtemperature. The coating time is preferably in a range of 1 minute to 12hours. After the immersion, the porous base material is dried in aconvection oven at 100° C. to 160° C. The drying time is preferably in arange of 10 minutes to 12 hours.

Regarding surface tension, the change in surface modification can beevaluated by measuring a critical wetting surface tension (CWST). Thecritical wetting surface tension is measured by a method relying on aset of solutions having a certain composition. Each solution has aspecific surface tension. The surface tension of these solutions is in arange of 25 to 92×10⁻⁵ N/cm with small unequal increments. In order tomeasure the surface tension of the membrane, the membrane is placed on awhite light table, a drop of solution having a certain surface tensionis applied to the surface of the membrane, and the time taken for thesolution droplet to permeate the membrane and then turns bright whiteshowing that light has been transmitted through the membrane isrecorded. In a case where the time taken for the solution droplet topermeate the membrane is equal to or shorter than 10 seconds, it isconsidered that the solution instantaneously wets the membrane. In acase where the time is longer than 10 seconds, it is considered that thesolution partially wets the membrane.

The pore size of the filter A according to the present embodiment is notparticularly limited. Generally, the pore size of the filter A ispreferably 1 nm to 10 μm, and more preferably 1 to 100 nm.

Second Embodiment of Filter A

Examples of a second embodiment of the filter A include a filter havinga porous base material made of polyfluorocarbon (typically,polytetrafluoroethylene, hereinafter, described aspolytetrafluoroethylene) and a coating layer which is disposed to coverat least a portion of the porous base material and contains a copolymerhaving the following unit A and unit B.

The unit A is represented by the following formula.

The unit B is represented by the following formula.

In the formula,

the copolymer is a block copolymer or a random copolymer, n and m arethe number of repeating units A and B present in the copolymer, arepreferably independently 1 to 1,000, and add up to 10 or greater, andthe copolymer in the coating layer may be crosslinked.

In the formulas shown in the present specification, the dotted line inthe formula of a repeating unit shows that the copolymer can be a blockcopolymer or a random copolymer. The block copolymer is sometimesrepresented by a bracket (repeating unit), and the random copolymer issometimes represented by a square bracket [repeating unit].

n and m represent a molar fraction of monomers present in the copolymer.n and m are preferably each independently in a range of 1 to 99 mol %,and more preferably each independently in a range of 20 to 50 mol %.

The copolymer can be a block copolymer or a random copolymer. The blockcopolymer can be a diblock copolymer (A-B), a triblock copolymer (A-B-Aor B-A-B), or a multiblock copolymer ((A-B)x). The copolymer canoptionally include a third segment C, for example, a triblock copolymeror a random copolymer such as A-B-C.

The copolymer has any suitable molecular weight. For example, in anembodiment, the number-average molecular weight (Mn) or weight-averagemolecular weight (Mw) of the copolymer is preferably 10,000 to1,000,000, more preferably 75,000 to 500,000, and even more preferably250,000 to 500,000.

The content (based on mass) of each monomer block in the block copolymeris not particularly limited. For example, the content ratio of twomonomer blocks can be 99:1 to 50:50 (all expressed as “% by mass”). Themonomer blocks can be present in the block copolymer preferably at acontent ratio of 90:10 to 70:30, and more preferably at a content ratioof 75:25 to 60:40.

The copolymer can have any suitable molecular chain end, for example, amolecular chain end which is selected from an aryl group and an alkoxygroup and preferably selected from a phenyl group and an ethoxy group.

As the anion, any appropriate anion such as fluoride, chloride, bromide,iodide, tosylate, mesylate, besylate, sulfonate, sulfate, phosphate, orphosphonate may be used.

Specific examples of the copolymer include those represented by thefollowing formulas.

The above copolymers can be prepared by any appropriate method, forexample, ring-opening metathesis polymerization (ROMP) of cyclicmonomers. Generally, a transition metal catalyst including a carbeneligand mediates the metathesis reaction. Examples of the method ofpreparing the copolymer include the methods described in paragraphs“0018” to “0033” of JP2016-194040A, and these methods are incorporatedinto the present specification.

Method of Preparing Filter A (Second Embodiment)

Next, typical examples of a method of preparing the filter A having theaforementioned coating layer will be described. For example, in themethod of preparing the filter A, the following steps are performed inorder.

-   -   Step of preparing porous base material made of        polytetrafluoroethylene    -   A step of coating the porous base material with a solution        containing a solvent and a copolymer so as to obtain a porous        base material with a coating layer    -   A step of drying the porous base material with a coating layer        so as to remove at least a part of the solvent

Furthermore, the preparation method may include the following steps.

-   -   A step of crosslinking the copolymer in the coating layer

The form of each of the above steps is the same as the form of each ofthe steps according to the first embodiment of the filter A. Therefore,the above steps will not be described.

Third Embodiment of Filter A

Examples of a third embodiment of the filter A include a filter having aporous base material made of polyfluorocarbon (typically,polytetrafluoroethylene, hereinafter, described aspolytetrafluoroethylene) and a coating layer which is disposed to coverat least a portion of the porous base material and has a crosslinkedpolymer network structure. The third embodiment of the filter A is afilter having a coating layer manufactured by coating a porous basematerial made of polytetrafluoroethylene with a coating compositionincluding a solvent, a crosslinker, a photoinitiator, and a telechelicpolymer and subjecting the obtained coating composition layer to in situcrosslinking, in which the telechelic polymer includes a main chainconsisting of polymerized 1,5-cyclooctadiene repeating units, at leastone of the repeating units includes a pendant adsorptive group bonded tothe main chain, and at least another one of the repeating units includesa pendant fluorinated hydrophobic group bonded to the main chain.

The telechelic polymer can have a hydrophobic group and/or a hydrophilicgroup as a terminal group. In an embodiment, the terminal group ishydrophobic. In other embodiments, the terminal group is hydrophilic.

For example, the telechelic polymer preferably has at least one kind ofunit selected from the group consisting of a unit B and a unit C, andmore preferably has a unit A. The units A to C are as follows.

In the formulas, the group represented by —S—R is an adsorptive grouphaving at least a thioether group.

R is not particularly limited, but is preferably at least one kind ofgroup selected from the group consisting of a carboxyalkyl group, asulfonalkyl group, and a hydroxyalkyl group.

The units A and B (A, B, and C in a case where the telechelic polymerhas C) in the telechelic polymer can be present as blocks or randomlyarranged blocks.

Specific examples of the telechelic polymer include those represented bythe following formula.

In the formula, in a case where n, m, and x represent the molar ratio ofeach unit, x and m are each independently 0 to 35 mol % of n+m+x. In acase where n, m, and x represent the number of repetitions of each unit,n+m+x=10 to 1,000, and n and m are each independently 10 to 1,000. R isan adsorptive group.

The telechelic polymer may have a hydrophilic terminal group. Examplesof the hydrophilic terminal group include a polyhydroxyalkyl ether groupand the like.

Specific examples of the telechelic polymer include those represented bythe following formula.

In the formula, R is preferably selected from the group consisting of,for example, a carboxyalkyl group, a sulfonalkyl group, and ahydroxyalkyl group, n is preferably 10 to 1,000, and P is a groupcapable of initiating polymerization (reactive substituent). In theabove formula, n, m, and x have the same definitions as n, m, and x inFormula (I). —S—R is an adsorptive group having at least a thioethergroup.

Specific examples of the telechelic polymer include those represented bythe following

In the formulas, in a case where n, m, and x represent the molar ratioof each unit, x and m are independently 0 to 35 mol % of n+m+x. In acase where n, m, and x represent the number of repetitions of each unit,n+m+x=10 to 1,000. —S—R is an adsorptive group having at least athioether group.

The telechelic polymer can be crosslinked using any appropriatecrosslinker which is preferably bi-thiol or multi-thiol.

It is possible to use any appropriate photoinitiator, for example, aphotoinitiator selected from camphorquinone, benzophenone, benzophenonederivatives, acetophenone, acetophenone derivatives, phosphine oxide andderivatives thereof, benzoin alkyl ether, benzyl ketal, phenylglyoxalester and derivatives thereof, dimeric phenylglyoxal ester, perester,halomethyltriazine, hexaarylbisimidazole/coinitiator-basedphotoinitiator, ferrocenium compounds, titanocene, and combinations ofthese.

The crosslinks of the coating layer are formed by exposing the coatingcomposition layer to UV radiation.

Other specific examples of the telechelic polymer include the followingones.

In the formulas, P is a group capable of initiating polymerization(reactive substituent). In a case where n, m, and x represent the molarratio of each unit, x and m are each independently 0 to 35 mol % ofn+m+x. In a case where n, m, and x represent the number of repetitionsof each unit, n+m+x=10 to 1,000. —S—R is an adsorptive group having atleast a thioether group.

Method of Preparing Filter A (Third Embodiment)

Next, typical examples of a method of preparing the filter A having theaforementioned coating layer will be described. For example, in themethod of preparing the filter A, the following steps are performed inorder.

-   -   Step of preparing porous base material made of        polytetrafluoroethylene    -   A step of coating the porous base material with a solution        (coating-forming composition) containing a solvent, a        crosslinker, a photoinitiator, and the aforementioned telechelic        polymer so as to obtain a porous base material with a layer of        the coating-forming composition    -   A step of drying the porous base material with a layer of the        coating-forming composition so as to remove at least a portion        of the solvent    -   A step of crosslinking the telechelic polymer in the layer of        the coating-forming composition

Hereinafter, the method of preparing the filter A according to the thirdembodiment will be described. The details that are not described beloware the same as those in the method of preparing the filter A accordingto the first embodiment described above.

The molecular weight of the telechelic polymer is not particularlylimited. For example, the number-average molecular weight (Mn) or theweight-average molecular weight (Mw) of the telechelic polymer ispreferably 10,000 to 1,000,000, more preferably 75,000 to 500,000, andeven more preferably 250,000 to 500,000.

The telechelic polymer can be prepared by any appropriate method, forexample, the ring-opening metathesis polymerization of1,5-cyclooctadiene (COD). Generally, a transition metal catalystincluding a carbene ligand mediates the metathesis reaction.

As the method of preparing the telechelic polymer, the methods describedin paragraphs “0025” to “0046” of JP2016-194037A can be referred to, andthese methods are incorporated into the present specification.

Fourth Embodiment of Filter A

Examples of a fourth embodiment of the filter A include a filter havinga porous base material made of polyfluorocarbon (typically,polytetrafluoroethylene, hereinafter, described aspolytetrafluoroethylene) and a coating layer which is disposed to coverat least a portion of the porous base material and contains thefollowing fluorinated polymer.

The fluorinated polymer according to the present embodiment isrepresented by Formula R—S—P. In the formula, R is a fluorocarbyl group,S is sulfur, and P is a copolymer of (i) polyglycerol; (ii) poly(allylglycidyl ether) and; and (iii) glycidol and allyl glycidyl ether havingone or more allyl groups or (iv) poly(allyl glycidyl ether) or glycidoland allyl glycidyl ether, in which one or more allyl groups aresubstituted with a 1,2-dihydroxypropyl group or a group represented byFormula —(CH₂)_(a)—S—(CH₂)_(b)—X (in the formula, a is 3, b is 1 to 3,and X is selected from an acid group, a base group, a cation, an anion,a zwitterion, a halogen, hydroxyl, acyl, acyloxy, alkylthio, alkoxy,aldehyde, amide, carbamoyl, ureido, cyano, nitro, epoxy, a grouprepresented by Formula —C(H)(COOH)(NH₂), a group represented by Formula—C(H)(COOH)(NHAc), or a salt thereof).

The fluorocarbyl group represented by R is not particularly limited, andexamples thereof include a fluoroalkyl group, a fluoroalkenyl group, afluorocycloalkyl group, and the like. The fluoroalkyl group and thefluoroalkenyl group may be linear or branched.

The fluorocarbyl group is preferably a fluoroalkyl group represented byFormula C_(n)F_(2n+1)(CH₂)_(m)— (in the formula, n and m are preferablyindependently 1 to 20, n is more preferably 4 to 12 and particularlypreferably 8, and m is more preferably 2 to 6 and particularlypreferably 2).

n is preferably 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,17, 18, 19 or 20.

m is preferably 1, 2, 3, 4, 5, or 6.

P is preferably a polymer of polyglycerol or glycidol. It is preferablethat the polyglycerol has one or more repeating units shown below.

It is preferable that the polyglycerol includes one or more structuresshown below.

The point of binding to the sulfur in Formula R—S—P is indicated byawavy line.

P preferably has one or more allyl groups. P is preferably a copolymerof glycidol and allyl glycidyl ether. For example, it is preferable thatthe copolymer P has the following structure.

P is preferably a polymer of allyl glycidyl ether in which the allylgroup is substituted with a functional group. For example, it ispreferable that P has one structure shown below.

In the formula, m is preferably 10 to 1,000, more preferably 30 to 300,and even more preferably 50 to 250.

P is preferably a copolymer of glycidol and allyl glycidyl ether, inwhich one or more allyl groups are substituted with a functional group.For example, it is preferable that P has the following structure.

In the formula, R is allyl and/or —(CH₂)_(b)—X.

For the block copolymer, X is preferably selected from an amino group, adimethylamino group, —CH₂CH₂SO₃H, —CH₂CH₂CH₂SO₃H, —CH₂CO₂H,—CH₂CH₂N⁺(CH₃)₃, and a combination of these.

Therefore, for example, it is preferable that P has at least one kind ofstructure selected from the group consisting of the followingstructures.

In addition, it is also preferable that the fluorinated polymer has thefollowing structure.

Furthermore, it is also preferable that the fluorinated polymer has thefollowing structure.

The fluorinated polymer can be prepared using a known method. As themethod of preparing the fluorinated polymer, it is possible to use themethods described in paragraphs “0022” to “0045” of JP2016-029146A, andthese methods are incorporated into the present specification.

Method of Preparing Filter A (Fourth Embodiment)

Next, typical examples of a method of preparing the filter A having theaforementioned coating layer will be described. For example, in themethod of preparing the filter A. the following steps are performed inorder

-   -   Step of preparing porous base material made of        polytetrafluoroethylene    -   A step of coating the porous base material with a solution        containing a solvent and the aforementioned fluorinated polymer        so as to obtain a porous base material with a coating layer    -   A step of drying the porous base material with a coating layer        so as to remove at least a part of the solvent

Hereinafter, the method of preparing the filter A according to thefourth embodiment will be described. The details that are not describedbelow are the same as those in the method of preparing the filter Aaccording to the first embodiment described above.

The solvent is not particularly limited and can be selected from water,alcohol solvents such as methanol, ethanol, and isopropanol, estersolvents such as ethyl acetate, propyl acetate, ethyl formate, propylformate, and amyl acetate, ketone solvents such as acetone, methyl ethylketone, and cyclohexanone, amide solvents such as N,N-dimethylformamide,N,N-dimethylacetamide, and N-methylpyrrolidone, cyclic ethers such asdioxane and dioxolane, and a mixture of these. In an embodiment, thesolvent is a mixture of methanol and water at a ratio of 50:50 v/v.

The fluorinated polymer can be present in the solution at an appropriateconcentration. For example, the concentration of the fluorinated polymeris preferably 0.01% to 5% by mass, more preferably 0.1% to 2% by mass,and even more preferably 0.25% to 1% by mass.

Before being coated, the porous base material can be optionallypreliminarily wet with isopropanol, ethanol, or methanol and rinsed withwater.

By bringing the porous base material into contact with the coatingsolution for an appropriate period of time, for example, for 1 minute to2 hours, preferably for 10 minutes to 1 hour, and more preferably for 20to 50 minutes, the coating layer can be formed.

The porous base material and the coating solution can be brought intocontact with each other by any appropriate method such as a method ofimmersing the porous base material in the coating solution, a method ofpassing the coating solution through the porous base material with orwithout creating a vacuum in the porous base material, meniscus coating,dip coating, spray coating, spin coating, or any combination of these.

The coating layer may be dried. The drying temperature is notparticularly limited, but is preferably equal to or higher than 40° C.,more preferably 60° C. to 160° C., even more preferably 70° C. to 115°C., and particularly preferably 80° C. to 110° C.

The heating time is not particularly limited. Generally, the heatingtime is preferably 1 minute to 2 hours, more preferably 10 minutes to 1hour, and even more preferably 20 to 40 minutes.

Furthermore, the coating layer may be washed with hot water, forexample, hot water at 80° C. for an appropriate period of time (forexample, 5 minutes to 2 hours) so as to totally remove free fluorinatedpolymers or water-soluble polymers, and then the coating layer may bedried at a temperature of 80° C. to 110° C. for 2 to 20 minutes.

The CWST of the coating layer is not particularly limited, but ispreferably higher than 72×10⁻⁵ N/cm and more preferably 73 to 95×10⁻⁵N/cm.

In order to measure CWST of the membrane, the first porous membrane isplaced on a white light table, a drop of solution having a certainsurface tension is applied to the surface of the membrane, and the timetaken for the solution droplet to penetrate and pass through themembrane and then turns bright white showing that light has passedthrough the membrane is recorded. In a case where the time taken for thesolution droplet to pass through the membrane is equal to or shorterthan 10 seconds, it is considered that the solution instantaneously wetsthe membrane. In a case where the time is longer than 10 seconds, it isconsidered that the solution partially wets the porous membrane. CWSTcan be selected by the methods known in the related art or selected asdisclosed in U.S. Pat. Nos. 5,152,905A, 5,443,743A, 5,472,621A, and6,074,869A.

Generally, the critical wetting surface tension (CWST) of the filter Ais preferably 27 to 60×10⁻⁵ N/cm, and more preferably 30 to 50×10⁻⁵N/cm. In a case where the critical wetting surface tension is in a rangeof 33 to 40×10⁻⁵ N/cm, the filter A can better remove metals.

The filter A according to the present embodiment remains stable eventhough the filter A is exposed, at room temperature, to a solutioncontaining 2% NaOH and 2,000 ppm of NaOCl for at least 7 days, to 5MNaOH for at least 7 days, or to 5M HCl for at least 7 days. In aplurality of embodiments, the filter A remains stable for up to 30 dayseven though the filter A is exposed to the aforementioned substances atroom temperature.

The filter A according to the present embodiment is resistant to thecontamination of the filter. For example, in a case where the filter Ais tested using surface water, the filter A exhibits a high permeateflow rate which is at least 7.0 mL/min/cm² for example, and the highpermeate flow rate is maintained in repeated cycles which are 5 or morecycles for example.

Fifth Embodiment of Filter A

Examples of a fifth embodiment of the filter A include a filter having aporous base material made of polyfluorocarbon (typically,polytetrafluoroethylene, hereinafter, described aspolytetrafluoroethylene) and a coating layer which is disposed to coverat least a portion of the porous base material and contains a copolymerhaving the following unit C and unit D.

The unit C is at least one kind of unit selected from the groupconsisting of the following formulas.

The unit D is represented by the following formula.

In the formula, n and m are preferably 1 to 1,000, and add up to 10 orgreater.

In a case where n and m represent a degree of polymerization of eachmonomer, n and m are preferably each independently 10 to 1,000, and morepreferably each independently 20 to 50.

In another embodiment, in a case where n and m represent a molarfraction of each monomer, n and m represent a molar fraction of amonomer present in a copolymer. n and m are preferably eachindependently 1 to 99 mol %, and more preferably each independently 20to 50 mol %.

The monomer blocks can be present in the block copolymer at anyappropriate ratio expressed as % by mass. For example, the mass ratio ofthe monomer blocks is preferably 99:1 to 50:50 (all expressed as % bymass), more preferably 90:10 to 70:30, and even more preferably 75:25 to60:40.

The copolymer can be a block copolymer or a random copolymer. The blockcopolymer can be a diblock copolymer (A-B), a triblock copolymer (A-B-Aor B-A-B), or a multiblock copolymer ((A-B)x). Furthermore, thecopolymer can include a third segment C, for example, a triblockcopolymer or a random copolymer such as A-B-C.

The molecular weight of the copolymer is not particularly limited.However, generally, the number-average molecular weight or theweight-average molecular weight (Mn or Mw) of the copolymer ispreferably 10,000 to 1,000,000, more preferably 75,000 to 500,000, andeven more preferably 250,000 to 500,000.

Specific examples of the copolymer include one of the followingformulas.

The copolymer may further include one or more repeating units Crepresented by the following formula.

In this case, the ratio of o/(m+n) is higher than 0 mol %, preferablyequal to or lower than 0.25 mol %, more preferably 0.05 to 0.25 mol %,and even more preferably 0.10 to 0.15 mol %.

Specific examples of the copolymer include those including the followingformula.

Modification Example of Fifth Embodiment of Filter A

Examples of the filter A according to the present embodiment include afilter having a porous base material made of polytetrafluoroethylene anda coating layer which is disposed to cover at least a portion of theporous base material and contains a polymer. The polymer has one or moreperfluoroalkylthio pendant groups bonded to the main chain. Therepeating unit of the polymer is represented by the following formula.

In the formula, * represents the point of binding to theperfluoroalkylthio pendant group.

Specifically, examples of the polymer include a polymer represented bythe following formula.

In the formula, p+q=m−1.

The perfluoroalkylthio pendant group can be present in some or all ofthe repeating units of the polymer. Accordingly, for example, the amountof the perfluoroalkylthio pendant group present in the repeating unitscan be greater than 0 mol % and equal to or smaller than 100 mol %. Inan embodiment, the amount of the perfluoroalkylthio pendant grouppresent in the repeating units can be 1 to 50 mol % or 10 to 30 mol %.The perfluoroalkylthio pendant groups are randomly arranged in thepolymer main chain.

The copolymer and polymer having a perfluoroalkylthio pendant groupaccording to the present embodiment can be prepared by any appropriatemethod such as ring-opening metathesis polymerization (ROMP) of a cyclicmonomer. Generally, a transition metal catalyst including a carbeneligand mediates the metathesis reaction. As the method of preparing thecopolymer and polymer described above, for example, it is possible touse the methods described in paragraphs “0021” to “0048” ofJP2016-196625A, and the description is incorporated into the presentspecification.

Method of Preparing Filter A (Fifth Embodiment)

Next, typical examples of a method of preparing the filter A having theaforementioned coating layer will be described. For example, in themethod of preparing the filter A, the following steps are performed inorder.

-   -   Step of preparing porous base material made of        polytetrafluoroethylene    -   A step of coating the porous base material with a solution        containing a solvent and the aforementioned copolymer or the        aforementioned polymer having a perfluoroalkylthio pendant group        so as to obtain a porous base material with a coating layer    -   A step of drying the coating layer so as to remove at least a        portion of the solvent from the solution containing the        copolymer or polymer eltm

In addition, the preparation method may further have the following step.

-   -   A step of crosslinking the copolymer or polymer present in the        coating layer

Hereinafter, the method of preparing the filter A according to thepresent embodiment will be described. The details that are not describedbelow are the same as those in the method of preparing the filter Aaccording to the first embodiment described above.

Crosslinks can be formed using any suitable method, for example, aphotoinitiator and high energy radiation such as ultraviolet. It isconsidered that the crosslinks will result in an extremely stablepolymer network structure for the membrane.

Examples of the photoinitiator include camphorquinone, benzophenone,benzophenone derivatives, acetophenone, acetophenone derivatives,phosphine oxide and derivatives thereof, benzoin alkyl ether, benzylketal, phenylglyoxal ester and derivatives thereof, dimericphenylglyoxal ester, perester, halomethyltriazine,hexaarylbisimidazole/coinitiator-based photoinitiator, ferroceniumcompounds, titanocene, and combinations of these.

The crosslinks can be formed as below. The porous base material with acoating layer is preliminarily wet with IPA, and then the sheet iswashed with a solvent in which a photoinitiator is prepared, such thatIPA is exchanged with the solvent. Thereafter, the sheet is immersed ina photoinitiator solution having a certain concentration for a certainperiod of time and then irradiated with UV. The time of immersion in thephotoinitiator solution is preferably in a range of 1 minute to 24hours. The UV irradiation time is preferably in a range of 30 seconds to24 hours.

<Filter BU>

The filter BU is a filter different from the filter A, and is arrangedin series with the filter A on the upstream side of the filter A on theflow path. In the present specification, “filter different from thefilter A” means a filter different from the filter A in terms of atleast one kind of item selected from the group consisting of material,pore size, and pore structure. “Upstream side” refers to the side of theinlet portion on the flow path.

Particularly, in view of obtaining a filtering device having furtherimproved effects of the present invention, the filter BU is preferablydifferent from the filter A in terms of at least one item selected fromthe group consisting of pore size and material.

The pore size of the filter BU is not particularly limited as long asthe filter has an arbitrary pore size used in the filtering device.Particularly, in view of obtaining a chemical liquid having furtherimproved defect inhibition performance, the pore size of the filter BUis preferably larger than the pore size of the filter A. Especially,pore size of the filter BU is preferably equal to or smaller than 200nm. The pore size of the filter BU is preferably equal to or greaterthan 10 nm, and more preferably equal to or greater than 20 nm.

According to the examination of the inventors of the present invention,it has been found that in a case where a filtering device is used inwhich the filter BU having a pore size equal to or greater than 20 nm isdisposed on the upstream side of the filter A on the flow path S1, it ismore difficult for the filter A to be clogged, and the pot life of thefilter A can be further extended. As a result, a filtering devicecapable of stably providing a chemical liquid having further improveddefect inhibition performance can be obtained.

The pore structure of the filter BU is not particularly limited. In thepresent specification, the pore structure of a filter means a pore sizedistribution, a positional distribution of pores in a filter, a poreshape, and the like. Typically, the pore structure can be controlled bythe manufacturing method of the filter.

For example, in a case where powder of a resin or the like is sinteredto form a membrane, a porous membrane is obtained. Furthermore, in acase where a methods such as electrospinning, electroblowing, and meltblowing are used to form a membrane, a fiber membrane is obtained. Thesehave different pore structures.

“Porous membrane” means a membrane which retains components in a liquidto be purified, such as gel, particles, colloids, cells, andpolyoligomers, but allows the components substantially smaller than thepores of the membrane to pass through the membrane. The retention ofcomponents in the liquid to be purified by the porous membrane dependson operating conditions, for example, the surface velocity, the use of asurfactant, the pH, and a combination of these in some cases.Furthermore, the retention of components can depend on the pore size andstructure of the porous membrane, and the size and structure ofparticles supposed to be removed (such as whether the particles are hardparticles or gel).

An ultra-high-molecular-weight polyethylene (UPE) filter is typically asieving membrane. A sieving membrane means a membrane that trapsparticles mainly through a sieving retention mechanism or a membranethat is optimized for trapping particles through a sieving retentionmechanism.

Typical examples of the sieving membrane include, but are not limitedto, a polytetrafluoroethylene (PTFE) membrane and a UPE membrane.

“Sieving retention mechanism” refers to the retention caused in a casewhere the particles to be removed are larger than the size of microporesof the porous membrane. Sieving retentivity can be improved by forming afilter cake (aggregate of particles to be removed on the surface of themembrane). The filter cake effectively functions as a secondary filter.

The pore structure of the porous membrane (for example, a porousmembrane including UPE, PTFE, and the like) is not particularly limited.The pores have, for example, a lace shape, a string shape, a node shape,and the like.

The size distribution of pores in the porous membrane and the positionaldistribution of pores size in the membrane are not particularly limited.The size distribution may be narrower, and the positional distributionof pore size in the membrane may be symmetric. Furthermore, the sizedistribution may be wider, and the positional distribution of pore sizein the membrane may be asymmetric (this membrane is also called“asymmetric porous membrane”). In the asymmetric porous membrane, thesize of the pores changes in the membrane. Typically, the pore sizeincreases toward the other surface of the membrane from one surface ofthe membrane. In this case, the surface containing pores having a largepore size is called “open side”, and the surface containing pores havinga small pore size is also called “tight side”.

Examples of the asymmetric porous membrane include a membrane in whichthe pore size is minimized at a position in the thickness direction ofthe membrane (this is also called “hourglass shape”).

In a case where the asymmetric porous membrane is used such that largepores are on the primary side (upstream side of the flow path), in otherwords, in a case where the primary side is used as the open side, apre-filtration effect can be exerted.

The porous membrane layer may include a thermoplastic polymer such aspolyethersulfone (PESU), perfluoroalkoxyalkane (PFA, a copolymer oftetrafluoroethylene and perfluoroalkoxyalkane), polyamide, or apolyolefin, or may include polytetrafluoroethylene and the like.

Particularly, as a material of the porous membrane,ultra-high-molecular-weight polyethylene is preferable. Theultra-high-molecular-weight polyethylene means thermoplasticpolyethylene having a very long chain. The molecular weight thereof isequal to or greater than 1,000,000. Typically, the molecular weightthereof is preferably 2,000,000 to 6,000,000.

For example, in a case where the liquid to be purified contains, asimpurities, particles containing an organic compound, such particles arenegatively charged in many cases. For removing such particles, a filtermade of polyamide functions as a non-sieving membrane. Typicalnon-sieving membranes include, but are not limited to, nylon membranessuch as a nylon-6 membrane and a nylon-6,6 membrane.

“Non-sieving” retention mechanism used in the present specificationrefers to retention resulting from the mechanism such as blocking,diffusion, and adsorption irrelevant to the pressure reduction of thefilter or the pore size of the filter.

The non-sieving retention includes a retention mechanism such asblocking, diffusion, and adsorption for removing particles supposed tobe removed from the liquid to be purified irrespective of the pressurereduction of the filter or the pore size of the filter. The adsorptionof particles onto the filter surface can be mediated, for example, bythe intermolecular van der Waals force and electrostatic force. In acase where the particles moving in the non-sieving membrane layer havinga serpiginous path cannot sufficiently rapidly change direction so asnot to contact the non-sieving membrane, a blocking effect is exerted.The transport of particles by diffusion is mainly caused by the randommotion or the Brownian motion of small particles that results in acertain probability that the particles may collide with the filtermedium. In a case where there is no repulsive force between theparticles and the filter, the non-sieving retention mechanism can beactivated.

The material of the fiber membrane is not particularly limited as longas it is a polymer capable of forming the fiber membrane. Examples ofthe polymer include polyamide and the like. Examples of the polyamideinclude nylon 6, nylon 6,6, and the like. The polymer forming the fibermembrane may be poly(ethersulfone). In a case where the fiber membraneis on the primary side of the porous membrane, it is preferable that thesurface energy of the fiber membrane is higher than the surface energyof the polymer which is the material of the porous membrane on asecondary side (downstream side of the flow path). For example, in somecases, nylon as a material of the fiber membrane and polyethylene (UPE)as the porous membrane are combined.

As the method for manufacturing the fiber membrane, known methods can beused without particular limitation. Examples of the method formanufacturing the fiber membrane include electrospinning,electroblowing, melt blowing, and the like.

Although the filtering device in FIG. 2 has one filter BU, the filteringdevice according to the present embodiment may have a plurality offilters BU. In this case, the relationship between the pore sizes of theplurality of filters BU is not particularly limited. However, in view ofeasily obtaining a chemical liquid having further improved defectinhibition performance, it is preferable that a filter BU disposed inthe uppermost stream on the flow path has the largest pore size. In acase where the filter BU having the largest pore size is positioned asdescribed above, the pot life of the filters (including the filter A)disposed in the downstream of the filter BU in the uppermost stream canbe further extended, and as a result, a filtering device capable ofstably providing a chemical liquid having further improved defectinhibition performance is obtained.

The material of the filter BU is not particularly limited, and thefilter BU may optionally contain an inorganic material (such as a metal,glass, or diatomite), an organic material, and the like. The material ofthe filter BU may be the same as the material of the filter A describedabove (in a case where material of the filter BU is the same as thematerial of the filter A, the filter B is different from the filter A interms of pore size and/or pore structure), or may be the same as thematerial of the filter BD which will be described later.

Particularly, in view of obtaining a filtering device having furtherimproved effects of the present invention, it is preferable that thefilter BU consists of a material capable of removing ions. In this case,it is preferable that the filter BU contains, as a material component(constituent component), a resin having an ion exchange group.

The ion exchange group is not particularly limited. However, in view ofobtaining a filtering device having further improved effects of thepresent invention, the ion exchange group is preferably at least onekind of ion exchange group selected from the group consisting of an acidgroup, a base group, an amide group, and an imide group.

As the filter BU, a material is more preferable which includes a basematerial such as polyfluorocarbon or polyolefin and an ion exchangegroup introduced into the base material.

Second Embodiment

FIG. 2 is a schematic view illustrating a filtering device according toa second embodiment of the present invention.

A filtering device 200 is a filtering device in which a filter 103 as afilter A and a filter 201 (filter BD) different from the filter 103 arearranged in series through a piping 202 between the inlet portion 101and the outlet portion 102.

The inlet portion 101, the filter 103, the piping 202, the filter 104,and the outlet portion 102 are constituted such that a liquid to bepurified can flow in the interior of each of these members. Thesemembers are connected to one another and form a flow path S2 (paththrough which the liquid to be purified flows).

In the filtering device 200, the form of each filter, piping, and thelike are the same as those of the filtering device according to thefirst embodiment described above. In the following section, only theparts different from the first embodiment will be described. Therefore,the matters that are not described below are the same as those of thefiltering device according to the first embodiment.

<Filter BD>

The filter BD is a filter different from the filter A, and is arrangedin series with the filter A on the downstream side of the filter A onthe flow path. “Downstream side” refers to the side of the outletportion on the flow path. Particularly, in view of obtaining a filteringdevice having further improved effects of the present invention, thefilter BD is preferably different from the filter A at least in terms ofpore size, and more preferably different from the filter A in terms ofpore size and material.

The pore size of the filter BD according to the present embodiment isnot particularly limited as long as it is smaller than the pore size ofthe filter A, and a filter having a pore size generally used forfiltering a liquid to be purified can be used. Particularly, the poresize of the filter is preferably equal to or smaller than 200 nm, morepreferably equal to or smaller than 20 nm, still more preferably equalto or smaller than 10 nm, particularly preferably equal to or smallerthan 5 nm, and most preferably equal to or smaller than 3 nm. The lowerlimit thereof is not particularly limited, but is generally preferablyequal to or greater than 1 nm from the viewpoint of productivity.

In a case where the liquid to be purified is filtered using the filterA, and fine particles are generated due to the filter A, sometimes thefine particles are mixed into the liquid to be purified. The filteringdevice according to the present embodiment has the filter BD at thedownstream on the flow path. Therefore, even though fine particles aregenerated due to the filter A, the fine particles can be separated fromthe liquid to be purified by filtration, and a chemical liquid havingfurther improved defect inhibition performance can be easily obtained.

Although the filtering device in FIG. 1 has one filter BD, the filteringdevice according to the present embodiment may have a plurality offilters BD. In this case, the relationship between the pore sizes of theplurality of filters BD is not particularly limited. However, in view ofeasily obtaining a chemical liquid having further improved defectinhibition performance, it is preferable that a filter BD disposed onthe downmost stream side on the flow path has the smallest pore size.

The material of the filter BD is not particularly limited, and may bethe same as or different from the material of the filter A.Particularly, in view of obtaining a filtering device having furtherimproved effects of the present invention, it is preferable that thematerial of the filter BD is different from that of the filter A.

The material of the filter BD is not particularly limited, and thoseknown as materials of filters can be used. Specifically, in a case wherethe material is a resin, it is preferable that the filter BD contains,as a material component, polyamide such as 6-nylon and 6,6-nylon;polyolefin such as polyethylene and polypropylene; polystyrene;polyimide; polyamideimide; poly(meth)acrylate; polyfluorocarbons such aspolytetrafluoroethylene, perfluoroalkoxyalkane, a perfluoroethylenepropene copolymer, an ethylene/tetrafluoroethylene copolymer, anethylene-chlorotrifluoroethylene copolymer, polychlorotrifluoroethylene,polyvinylidene fluoride, and polyvinyl fluoride; polyvinyl alcohol;polyester; cellulose; cellulose acetate, and the like. Among these, inview of obtaining further improved solvent resistance and obtaining achemical liquid having further improved defect inhibition performance,at least one kind of resin is preferable which is selected from thegroup consisting of nylon (particularly preferably 6,6-nylon),polyolefin (particularly preferably polyethylene), poly(meth)acrylate,and polyfluorocarbon (particularly preferably polytetrafluoroethylene(PTFE) and perfluoroalkoxyalkane (PFA)). One kind of each of thesepolymers can be used singly, or two or more kinds of these polymers canbe used in combination.

In addition to the resin, diatomite, glass, and the like may also beused.

Furthermore, the filter may be subjected to surface treatment. As thesurface treatment method, known methods can be used without particularlimitation. Examples of the surface treatment method include a chemicalmodification treatment, a plasma treatment, a hydrophobizationtreatment, coating, a gas treatment, sintering, and the like.

The plasma treatment is preferable because the surface of the filter ishydrophilized by this treatment. Although the water contact angle on thesurface of each filter hydrophilized by the plasma treatment is notparticularly limited, a static contact angle measured at 25° C. by usinga contact angle meter is preferably equal to or smaller than 60°, morepreferably equal to or smaller than 50°, and even more preferably equalto or smaller than 30°.

As the chemical modification treatment, a method of introducing ionexchange groups into the base material is preferable.

That is, the filter is preferably obtained by using materials containingthe components exemplified above as a base material and introducing ionexchange groups into the base material. Typically, it is preferable thatthe filter includes a layer, which includes a base material having ionexchange groups, on a surface of the base material described above.Although there is no particular limitation, as the surface-treated basematerial, a base material obtained by introducing ion exchange groupsinto the aforementioned polymer is preferable because the manufacturingof such a base material is easier.

Examples of the ion exchange groups include cation exchange groups suchas a sulfonic acid group, a carboxy group, and a phosphoric acid groupand anion exchange groups such as a quaternary ammonium group. Themethod for introducing ion exchange groups into the polymer is notparticularly limited, and examples thereof include a method of reactinga compound, which has ion exchange groups and polymerizable groups, withthe polymer such that the compound is grafted on the polymer typically.

The method for introducing the ion exchange groups is not particularlylimited. In a case where the aforementioned resin fiber is irradiatedwith ionizing radiation (such as a-rays, β-rays, γ-rays, X-rays, orelectron beams), active portions (radicals) are generated in the resin.The irradiated resin is immersed in a monomer-containing solution suchthat the monomer is graft-polymerize with the base material. As aresult, a product is generated in which the monomer is bonded topolyolefin fiber as a side chain by graft polymerization. By bringingthe resin having the generated polymer as a side chain into contact witha compound having an anion exchange group or a cation exchange group soas to cause a reaction, an end product is obtained in which the ionexchange group is introduced into the polymer of the graft-polymerizedside chain.

Furthermore, the filter may be constituted with woven cloth or nonwovencloth, in which ion exchange groups are formed by a radiation graftpolymerization method, combined with glass wool, woven cloth, ornonwoven filter material that is conventionally used.

Particularly, in view of obtaining a filtering device having furtherimproved effects of the present invention, the component (materialcomponent) of the filter BD preferably contains at least one kind ofresin selected from the group consisting of polyolefin, polyamide,polyfluorocarbon, polystyrene, polysulfone, and polyethersulfone, andmore preferably consists of at least one kind of resin selected from thegroup consisting of polyolefin, polyamide, and polyfluorocarbon.

Examples of the polyolefin include polyethylene, polypropylene, and thelike. Among these, ultra-high-molecular-weight polyethylene ispreferable. Examples of the polyamide include 6-nylon, 6,6-nylon, andthe like. Examples of the polyfluorocarbon includepolytetrafluoroethylene, perfluoroalkoxyalkane, a perfluoroethylenepropene copolymer, an ethylene-tetrafluoroethylene copolymer, anethylene-chlorotrifluoroethylene copolymer, polychlorotrifluoroethylene,polyvinylidene fluoride, polyvinyl fluoride, and the like. Among these,at least one kind of compound selected from the group consisting ofpolyethylene and nylon is preferable, and in another embodiment,polytetrafluoroethylene is preferable.

Furthermore, it is also preferable that the filter BD contains a secondresin having a hydrophilic group. The hydrophilic group is notparticularly limited, and examples thereof include a hydroxyl group, anether group, an oxyalkylene group, a polyoxyalkylene group, a carboxylicacid group, an ester group, a carbonic acid ester group, a thiol group,a thioether group, a phosphoric acid group, and a phosphoric acid estergroup, an amide group, an imide group, and the like. Among them, ahydrophilic group different from the hydrophilic group of the filter Ais preferable, and at least one kind of hydrophilic group is preferablewhich is selected from the group consisting of a hydroxyl group, acarboxylic acid group, an ester group, a carbonic acid ester group, athiol group, a thioether group, a phosphoric acid group, a phosphoricacid ester group, an amide group, and an imide group.

The second resin is not particularly limited, but is preferably at leastone kind of resin selected from the group consisting of polyolefin,polyamide, polyfluorocarbon, polystyrene, polysulfone, andpolyethersulfone. Furthermore, as another embodiment, polyether,novolak, a cycloolefin polymer, polylactic acid, and the like are alsopreferable.

The pore structure of the filter BD is not particularly limited, and maybe appropriately selected according to the components of the liquid tobe purified.

Modification Example of Filtering Device According to Second Embodiment

FIG. 3 is a schematic view of a filtering device illustrating amodification example of a filtering device according to a secondembodiment of the present invention. A filtering device 300 includes afilter 103 as a filter A, a filter 104 as a filter BU, and a filter 201as a filter BD between an inlet portion 101 and an outlet portion 102 inwhich the filter 104, the filter 103, and the filter 201 are arranged inseries through a piping 301 and a piping 302.

In the filtering device 300, the form of each filter, piping, and thelike are the same as those of the filtering device according to thefirst embodiment described above. In the following section, only theparts different from the first embodiment will be described. Therefore,the matters that are not described below are the same as those of thefiltering device according to the first embodiment.

The inlet portion 101, the filter 104, the piping 301, the filter 103,the piping 302, and the filter 201 are constituted such that a liquid tobe purified can flow in the interior of each of these members. Thesemembers are connected to one another and form a flow path S3 (paththrough which the liquid to be purified flows). The constitutions of thepiping and each filter are as described above.

The filtering device 300 has the filter BU on the upstream side of thefilter A on the flow path. Therefore, the pot life of the filter A isfurther extended. Furthermore, the filtering device 300 has the filterBD on the downstream side of the filter A on the flow path. Therefore,the fine particles mixed into the liquid to be purified due to thefilter A can be efficiently removed, and as a result, a chemical liquidhaving further improved defect inhibition performance can be easilyobtained.

Third Embodiment

FIG. 4 is a schematic view illustrating a filtering device according toa third embodiment of the present invention.

A filtering device 400 further includes a tank 401 disposed in serieswith a filter A on the upstream side of the filter 104 (filter BU) on aflow path S4 between the inlet portion 101 and the outlet portion 102.The tank 401, the filter 104 (filter BU), and the filter 103 (filter A)are arranged in series through a piping 402 and the piping 105. The tank401 constitutes the flow path S4 together with the filters, pipings, andthe like described above.

In the filtering device 400, the form of each filter, piping, and thelike are the same as those of the filtering device according to thefirst embodiment described above. In the following section, only theparts different from the first embodiment will be described. Therefore,the matters that are not described below are the same as those of thefiltering device according to the first embodiment.

The filtering device according to the present embodiment has a tank onthe upstream side of the filter 104. Therefore, the liquid to bepurified that will flow through the filter 104 can be retained in thetank and can be homogenized. As a result, a chemical liquid havingfurther improved defect inhibition performance is obtained.Particularly, in a case where circulation filtration, which will bedescribed later, is performed, and the liquid to be purified is returnedto the upstream side of a first reference filter, which consists of atleast one kind of filter selected from the group consisting of thefilter 104 (filter BU) and the filter 103 (filter A), in the flow pathS4 from the downstream side of the first reference filter in the flowpath S4, the tank 401 can be used to receive the returned liquid to bepurified. In a case where the tank 401 is used as described above, thereturned liquid to be purified can be retained in the tank, homogenized,and passed again through the subsequent filters. Therefore, a chemicalliquid having further improved defect inhibition performance isobtained.

The material of the tank 401 is not particularly limited, and the samematerial as the material of the housing described above can be used. Itis preferable that at least a portion of the liquid contact portion ofthe tank 401 (preferably 90% or more of the surface area of the liquidcontact portion, and more preferably 99% or more of the surface area ofthe liquid contact portion) consists of the anticorrosive material whichwill be described later.

Modification Example of Filtering Device According to Third Embodiment

FIG. 5 is a schematic view illustrating a modification example of thefiltering device according to the third embodiment of the presentinvention.

A filtering device 500 further includes the tank 401 disposed in serieson the downstream side of the filter 104 (filter BU) on a flow path S5between the inlet portion 101 and the outlet portion 102. The filter 104(filter BU), the tank 401, and the filter 103 (filter A) are arranged inseries through a piping 501 and a piping 502. The tank 401 constitutes aflow path S5 together with the filters, pipings, and the like describedabove.

In the filtering device 500, the form of each filter, piping, and thelike are the same as those of the filtering device according to thefirst embodiment described above. In the following section, only theparts different from the first embodiment will be described. Therefore,the matters that are not described below are the same as those of thefiltering device according to the first embodiment.

The filtering device according to the present embodiment has a tank onthe downstream side of the filter BU. Therefore, the liquid to bepurified filtered through the filter BU can be retained in the tank.Particularly, in a case where circulation filtration, which will bedescribed later, is performed, and the liquid to be purified is returnedto the upstream side of the filter 103 in the flow path S5 from thedownstream side of the filter 103 (filter A) in the flow path S5, thetank 401 can be used to retain the returned liquid to be purified. In acase where the tank 401 is used as described above, the returned liquidto be purified can be retained in the tank, homogenized, and passedagain through the filter 103. Therefore, a chemical liquid havingfurther improved defect inhibition performance is obtained.

In the filtering device 500 according to the present embodiment, thetank 401 is disposed on the upstream side of the filter 103 (filter A)on the flow path S5. However, in the filtering device according to thepresent embodiment, the tank 401 may be disposed on the downstream sideof the filter 103 on the flow path S5.

As described above, the tank 401 can be used to retain the returnedliquid to be purified during circulation filtration. In other words, thetank 401 can be a starting point of the circulation filtration. In thiscase, either a filter on the downstream side of the tank 401 (filter 103in the filtering device 500) or a filter on the upstream side of thetank 401 (filter 104 in the filtering device 500) on the flow path S5 isfrequently used as a filter for circulation filtration. The startingpoint of the circulation filtration includes a starting point in a casewhere the tank constitutes a return flow path or a starting point in acase where a piping on the upstream or downstream side of the tankconstitutes a return flow path.

In the filtering device 500, the tank 401 is disposed on the upstreamside of the filter 103 (filter A). In a case where the tank 401 isdisposed on the upstream side of the filter 103 (filter A), andfiltration is repeated in the portion after the tank 401 in the flowpath S5 during circulation filtration, it is possible to adopt a flow inwhich particle-like impurities are finally removed using the filter 103(filter A) from the liquid to be purified filtered through the filter BU(for example, a filter having ion exchange groups).

The filtering device according to the present embodiment may be in theform of a filtering device in which the filter A and the filter BD arearranged in series in this order (for example, the second embodiment),and in the form of a filtering device in which the filter BU, the filterA, and the filter BD are arranged in series in this order (for example,a modification example of the second embodiment), and the tank 401 isfurther provided on the upstream or downstream side of the filter A.

Fourth Embodiment

FIG. 6 is a schematic view illustrating a filtering device according toa fourth embodiment of the present invention.

A filtering device 600 includes a filter 601 as a filter C, a tank 401,a filter 104 as a filter BU, and a filter 103 as a filter A that arearranged in series through a piping 602, a piping 402, and a piping 105between an inlet portion 101 and an outlet portion 102.

In the filtering device 600, the inlet portion 101, the filter 601, thepiping 602, the tank 401, the piping 402, the filter 104, the piping105, the filter 103, and the outlet portion 102 form a flow path S6.

In the filtering device 600, the form of each filter, piping, and thelike are the same as those of the filtering device according to thefirst embodiment described above. In the following section, only theparts different from the first embodiment will be described. Therefore,the matters that are not described below are the same as those of thefiltering device according to the first embodiment.

The filter 601 (filter C) is a filter which is disposed on the upstreamside of the tank 401 in the flow path S6 and has a pore size equal to orgreater than 20 nm. In the filtering device according to the presentembodiment, a filter having a predetermined pore size is disposed on theupstream side of the tank 401 in the flow path S6. Therefore, impuritiesand the like contained in the liquid to be purified flowing into thefiltering device from the inlet portion 101 can be removed in advance byusing the filter 601. Therefore, it is possible to further reduce theamount of impurities mixed into the flow path after the piping 602.Accordingly, the pot life of the subsequent filter BU and filter A (orthe filter BD in a case where the filter BD is disposed in the flowpath) can be further extended. Consequently, with the filtering devicedescribed above, it is possible to stably manufacture a chemical liquidhaving further improved defect inhibition performance.

The form of the filter C is not particularly limited, and the filter Cmay be the same filter as the filter A described above or a differentfilter (filter B). Particularly, in view of easily obtaining a chemicalliquid having further improved defect inhibition performance, the filterCis preferably the filter B. Especially, as the material and porestructure of the filter C, those described as the material and porestructure of the filter BD are preferable. The pore size of the filter Cmay be equal to or greater than 20 nm, and is preferably equal to orgreater than 50 nm. The upper limit thereof is not particularly limited,but is preferably equal to or smaller than 250 nm in general.

The filtering device according to the present embodiment may be in theform of a filtering device in which the filter A and the filter BD arearranged in series in this order on the flow path (for example, thesecond embodiment), and in the form of a filtering device in which thefilter BU, the filter A, and the filter BD are arranged in series inthis order on the flow path (for example, a modification example of thesecond embodiment), a tank is further provided on the downstream side ofthe filter A, and the filter C is provided on the upstream side of thetank.

Fifth Embodiment

FIG. 7 is a schematic view of a filtering device according to a fifthembodiment of the present invention. A filtering device 700 includes aninlet portion 101, an outlet portion 102, a filter 104 as a filter BU,and a filter 103 as a filter A, in which the filter 104 and the filter103 are arranged in series between the inlet portion 101 and the outletportion 102, and a flow path

S7 extending from the inlet portion 101 to the outlet portion 102 isformed. In the filtering device 700, the inlet portion 101, the filter104, a piping 105, the filter 103, and the outlet portion 102 form theflow path S7.

In the filtering device 700, the form of each filter, piping, and thelike are the same as those of the filtering device according to thefirst embodiment described above. In the following section, only theparts different from the first embodiment will be described. Therefore,the matters that are not described below are the same as those of thefiltering device according to the first embodiment.

In the filtering device 700, a return flow path R7 is formed which iscapable of returning the liquid to be purified can be to the upstreamside of the filter 104 in the flow path S7 from the downstream side ofthe filter 104 (and the filter 103) in the flow path S7. Specifically,the filtering device 700 has a piping 701 for return, and the piping 701forms a return flow path R7. One end of the piping 701 is connected tothe flow path S7 on the downstream side of the filter 104 (and thefilter 103) and the other end thereof is connected to the flow path S7on the upstream side of the filter 104. On the return flow path R7, apump, a damper, a valve, and the like not shown in the drawing may bearranged. Particularly, it is preferable to dispose a valve inconnection portions J1 and J2 shown in FIG. 7 so as to control theliquid to be purified such that the liquid does not unintentionally flowthrough the return flow path.

The liquid to be purified that has flowed through the return flow pathR7 and has been returned to the upstream side of the filter 104 (in theflow path S7) is filtered through the filter 104 and the filter 103 inthe process of flowing again through the flow path S7. This process iscalled circulation filtration. The filtering device 700 can perform thecirculation filtration, and as a result, a chemical liquid havingfurther improved defect inhibition performance is easily obtained.

In FIG. 7 , the piping 701 is disposed on the flow path S7 such that theliquid to be purified can be returned to the upstream side of the filter104 (filter BU) from the downstream side of the filter 103 (filter A).That is, the filtering device has a return flow path in which the filter104 is adopted as a first reference filter and through which the liquidto be purified can be returned to the upstream side of the firstreference filter from the downstream side of the first reference filter.The filtering device according to the present embodiment is not limitedto the above, and may have a return flow path in which the filter 103(filter A) is adopted as a first reference filter and through which theliquid to be purified can be returned to a position that is on thedownstream side of the filter 104 and on the upstream side of the filter103 from the downstream side of the filter 103.

In FIG. 7 , the return flow path R7 is formed only of piping. However,the return flow path R7 may be formed of one or plural tanks and pipingsdescribed above.

FIG. 8 is a schematic view illustrating a modification example of thefiltering device according to the fifth embodiment of the presentinvention.

The filtering device 800 has an inlet portion 101, tanks 401(a) and 401(b), an outlet portion 102, a filter 103 as a filter A, and a filter 104as a filter BU. The tank 401(a), filter 104, the filter 103, and thetank 401(b) are arranged in series between the inlet portion 101 and theoutlet portion 102, and the inlet portion 101, the tank 401(a), a piping802, the filter 104, a piping 803, the filter 103, a piping 804, thetank 401(b), and the outlet portion 102 form a flow path S8.

In the filtering device 800, the form of each filter, piping, and thelike are the same as those of the filtering device according to thefirst embodiment described above. In the following section, only theparts different from the first embodiment will be described. Therefore,the matters that are not described below are the same as those of thefiltering device according to the first embodiment.

In the filtering device 800, a return flow path R8 is formed which iscapable of returning the liquid to be purified to the upstream side ofthe tank 401(a) disposed on the upstream side of the filter 103 on theflow path S8 from the downstream side of the tank 401(b) disposed on thedownstream side of the filter 103 on the flow path S8. One end of apiping 801 is connected to the flow path S8 on the downstream side ofthe tank 401(b), and the other end thereof is connected to the flow pathS8 on the upstream side of the tank 401(a). On the return flow path R8,a pump, a damper, a valve, and the like not shown in the drawing may bearranged.

In the filtering device according to the present embodiment, thestarting point of the return flow path R8 is disposed on the downstreamside of the tank 401(b) on the flow path, and the end point of thereturn flow path R8 is disposed on the upstream side of the tank 401(a)on the flow path. In a case where the return flow path is constituted asdescribed above, during circulation filtration, the liquid to bepurified can be returned after being retained or can flow again afterbeing retained even after the liquid is returned. As a result, achemical liquid having further improved defect inhibition performancecan be obtained. The filtering device according to the presentembodiment may be in the form of a filtering device in which the tank401(b) and the piping 801 are directly connected to each other, in theform of a filtering device in which the tank 401(a) and the piping 801are directly connected to each other, or in the form of a filteringdevice as a combination of these.

Sixth Embodiment

FIG. 9 is a schematic view of a filtering device according to a fifthembodiment of the present invention. A filtering device 900 includes aninlet portion 101, an outlet portion 102, a filter 104 as a filter BU,and a filter 103 as a filter A, in which the filter 104 and the filter103 are arranged in series between the inlet portion 101 and the outletportion 102, and a flow path S9 extending from the inlet portion 101 tothe outlet portion 102 is formed.

In the filtering device 900, the inlet portion 101, the filter 104, apiping 105, the filter 103, and the outlet portion 102 form the flowpath S9.

In the filtering device 900, the form of each filter, piping, and thelike are the same as those of the filtering device according to thefirst embodiment described above. In the following section, only theparts different from the first embodiment will be described. Therefore,the matters that are not described below are the same as those of thefiltering device according to the first embodiment.

In the filtering device 900, a return flow path R9 is formed which iscapable of returning the liquid to be purified to a position that is onthe downstream side of the filter 104 and on the upstream side of thefilter 103 on the flow path S9 from the downstream side of the filter103 on the flow path S9. One end of the piping 901 is connected to theflow path S9 on the downstream side of the filter 103, and the other endthereof is connected to the flow path S9 at a position which is on theupstream side of the filter 103 and on the downstream side of the filter104. Specifically, the filtering device 900 has a piping 901 for return,and the piping 901 forms a return flow path R9. On the return flow pathR9, a pump, a damper, a valve, and the like not shown in the drawing maybe arranged.

The liquid to be purified that has flowed through the return flow pathR9 and has been returned to a position, which is on the downstream sideof the filter 104 and on the upstream side of the filter 103, isfiltered through the filter 103 in the process of flowing again throughthe flow path S9. Particularly, in a case where the filter 104 is afilter containing a resin having ion exchange groups as a materialcomponent, it is possible to remove particle-like impurities from theliquid to be purified filtered through the filter 104 by using thefilter 103 by means of circulation filtration. As a result, a chemicalliquid having further improved defect inhibition performance can beeasily obtained.

In FIG. 9 , the piping 901 is disposed such that the liquid to bepurified can be returned to a position, which is on the downstream sideof the filter BU and on the upstream side of the filter A on the flowpath S9, from the downstream side of the filter 103 (filter A: firstreference filter) on the flow path S9. However, in the filtering deviceaccording to the present embodiment, in a case where the filter A andthe filter BD are arranged in series in this order on the flow path, theflow path may be formed such that the liquid to be purified can bereturned to a position, which is on the upstream side of the filter BDor on the upstream side of the filter A on the flow path, from thedownstream side of the filter BD (second reference filter).

FIG. 10 is a schematic view illustrating a modification example of thefiltering device according to the present embodiment. A filtering device1000 includes an inlet portion 101, an outlet portion 102, a filter104-1 as a filter BU, a filter 104-2 (first reference filter) as afilter BU, and a filter 103, in which the filter 104-1, the filter104-2, and the filter 103 are arranged in series between the inletportion 101 and the outlet portion 102, and a flow path S10 extendingfrom the inlet portion 101 to the outlet portion 102 is formed.

In the filtering device 1000, the inlet portion 101, the filter 104-1, apiping 1001, the filter 104-2, a piping 1002, the filter 103, and theoutlet portion 102 form the flow path 510.

In the filtering device 1000, the form of each filter, piping, and thelike are the same as those of the filtering device according to thefirst embodiment described above. In the following section, only theparts different from the first embodiment will be described. Therefore,the matters that are not described below are the same as those of thefiltering device according to the first embodiment.

In the filtering device 1000, a return flow path R10 is formed which iscapable of returning the liquid to be purified to a position, which isthe downstream of the filter 104-1 and the upstream of the filter 104-2(first reference filter) in the flow path S10, from the downstream ofthe filter 104-2 (first reference filter) on the flow path 510. One endof the piping 1003 is connected to the flow path S10 at a position whichis on the upstream side of the filter 103 and on the downstream side ofthe filter 104-2, and the other end thereof is connected to the flowpath S10 at a position which is on the downstream side of the filter104-1 and on the upstream side of the filter 104-2. Specifically, thefiltering device 1000 has a piping 1003 for return, and the piping 1003forms a return flow path R10. On the return flow path R10, a pump, adamper, a valve, and the like not shown in the drawing may be arranged.

The liquid to be purified that has been returned to a position, which ison the downstream side of the filter 104-1 and on the upstream side ofthe filter 104-2 on the flow path S10. through the return flow path R10is filtered through the filter 104-2 in the process of flowing againthrough the flow path S10. The filtering device 1000 can performcirculation filtration. As a result, a chemical liquid having furtherimproved defect inhibition performance can be easily obtained.

In the filtering device shown in FIG. 10 , the return flow path R10 isformed which is capable of returning the liquid to be purified to theupstream side of the filter 104-2 from the downstream side of the filter104-2 on the flow path S10, that is, from the upstream side of thefilter 103. However, the filtering device according to the presentembodiment is not limited thereto, and may be a filtering device inwhich a return flow path capable of returning the liquid to be purifiedto the upstream side of the filter 104-1 from the downstream side of thefilter 104-2 is formed, or the like.

Furthermore, a filtering device, in which the filter A, the filter BD(referred to as filter BD-1), and the filter BD (referred to as filterBD-2) are arranged in series in this order on the flow path, may have areturn flow path capable of returning the liquid to be purified to theupstream side of the filter BD-1 (the upstream side may be a positionwhich is on the upstream side of the filter BD-1 and on either thedownstream side or the upstream side of the filter A) from thedownstream side of the filter BD-1 (second reference filter) (thedownstream side may be a position which is on either the upstream sideof the filter BD-2 or the downstream side of the filter BD-2).

Method for Manufacturing Chemical Liquid (First Embodiment)

The method for manufacturing a chemical liquid according to anembodiment of the present invention is a chemical liquid manufacturingmethod for obtaining a chemical liquid by purifying a liquid to bepurified. The method has a filtration step of filtering a liquid to bepurified by using the filtering device described above so as to obtain achemical liquid.

[Liquid to be Purified]

The liquid to be purified to which the method for manufacturing achemical liquid according to the embodiment of the present invention canbe applied is not particularly limited. However, it is preferable thatthe liquid to be purified contains a solvent. Examples of the solventinclude an organic solvent, and water, and the like. It is preferablethat the liquid to be purified contains an organic solvent. In thefollowing description, the liquid to be purified will be divided into anorganic solvent-based liquid to be purified in which the content of anorganic solvent (total content in a case where the liquid to be purifiedcontains a plurality of organic solvents) with respect to the total massof solvents contained in the liquid to be purified is greater than 50%by mass, and an aqueous liquid to be purified in which the content ofwater with respect to the total mass of solvents contained in the liquidto be purified is greater than 50% by mass.

<Organic Solvent-Based Liquid to be Purified>

(Organic Solvent)

The organic solvent-based liquid to be purified contains an organicsolvent, in which the content of the organic solvent is greater than 50%by mass with respect to the total mass of solvents contained in theliquid to be purified.

The content of the organic solvent in the organic solvent-based liquidto be purified is not particularly limited, but is preferably equal toor greater than 99.0% by mass with respect to the total mass of theorganic solvent-based liquid to be purified in general. The upper limitthereof is not particularly limited, but is preferably equal to orsmaller than 99.99999% by mass in general.

One kind of organic solvent may be used singly, or two or more kinds oforganic solvents may be used in combination. In a case where two or morekinds of organic solvents are used in combination, the total contentthereof is preferably within the above range.

In the present specification, an organic solvent means one liquidorganic compound which is contained in the liquid to be purified in anamount greater than 10,000 ppm by mass with respect to the total mass ofthe liquid to be purified. That is, in the present specification, aliquid organic compound contained in the liquid to be purified in anamount greater than 10,000 ppm by mass with respect to the total mass ofthe liquid to be purified corresponds to an organic solvent.

In the present specification, “liquid” means that the compound stays inliquid form at 25° C. under atmospheric pressure.

The type of the organic solvent is not particularly limited, and knownorganic solvents can be used. Examples of the organic solvent includealkylene glycol monoalkyl ether carboxylate, alkylene glycol monoalkylether, a lactic acid alkyl ester, alkyl alkoxypropionate, cyclic lactone(preferably having 4 to 10 carbon atoms), a monoketone compound whichmay have a ring (preferably having 4 to 10 carbon atoms), alkylenecarbonate, alkoxyalkyl acetate, alkyl pyruvate, and the like.

Furthermore, as the organic solvent, for example, those described inJP2016-057614A, JP2014-219664A, JP2016-138219A, and JP2015-135379A mayalso be used.

As the organic solvent, at least one kind of compound is preferablewhich is selected from the group consisting of propylene glycolmonomethyl ether (PGMM), ropylene glycol monoethyl ether (PGME),propylene glycol monopropyl ether (PGMP), propylene glycol monomethylether acetate (PGMEA), ethyl lactate (EL), methyl methoxypropionate(MPM), cyclopentanone (CyPn), cyclohexanone (CyHe), y-butyrolactone(yBL), diisoamyl ether (DIAE), butyl acetate (nBA), isoamyl acetate(iAA), isopropanol (IPA), 4-methyl-2-pentanol (MIBC), dimethylsulfoxide(DMSO), n-methyl-2-pyrrolidone (NMP), diethylene glycol (DEG), ethyleneglycol (EG), dipropylene glycol (DPG), propylene glycol (PG), ethylenecarbonate (EC), propylene carbonate (PC), sulfolane, cycloheptanone, and2-heptanone (MAK).

The type and content of the organic solvent in the liquid to be purifiedcan be measured using a gas chromatography mass spectrometer.

(Other Components)

The liquid to be purified may contain other components in addition tothe above components. Examples of those other components include aninorganic substance (such as metal ions, metal particles, and metaloxide particles), a resin, an organic substance other than a resin,water, and the like.

Inorganic Substance

The liquid to be purified may contain an inorganic substance. Theinorganic substance is not particularly limited, and examples thereofinclude metal ions, metal-containing particles, and the like.

The form of the metal-containing particles is not particularly limitedas long as the particles contain metal atoms. For example, themetal-containing particles are in the form of simple metal atoms,compounds containing metal atoms (hereinafter, also referred to as“metal compound”), a complex of these, and the like. Furthermore, themetal-containing particles may contain a plurality of metal atoms.

The complex is not particularly limited, and examples thereof include aso-called core-shell type particle having a simple metal atom and ametal compound covering at least a portion of the simple metal atom, asolid solution particle including a metal atom and another atom, aeutectic particle including a metal atom and another atom, an aggregateparticle of a simple metal atom and a metal compound, an aggregateparticle of different kinds of metal compounds, a metal compound inwhich the composition thereof continuously or intermittently changestoward the center of the particle from the surface of the particle, andthe like.

The atom other than the metal atom contained in the metal compound isnot particularly limited, and examples thereof include a carbon atom, anoxygen atom, a nitrogen atom, a hydrogen atom, a sulfur atom, aphosphorus atom, and the like. Among these, an oxygen atom ispreferable.

The metal atom is not particularly limited, and examples thereof includea Fe atom, an Al atom, a Cr atom, a Ni atom, a Pb atom, a Zn atom, a Tiatom, and the like. The metal-containing particles may contain one kindof each of the aforementioned metal atoms singly or may contain two ormore kinds of the aforementioned metal atoms in combination.

The particle size of the metal-containing particles is not particularlylimited, but is generally 1 to 100 nm in many cases.

The inorganic substance may be added to the liquid to be purified, ormay be unintentionally mixed into the liquid to be purified in themanufacturing process. Examples of the case where the inorganicsubstance is unintentionally mixed into the liquid to be purified in themanufacturing process of the chemical liquid include, but are notlimited to, a case where the inorganic substance is contained in a rawmaterial (for example, an organic solvent) used for manufacturing thechemical liquid, a case where the inorganic substance is mixed into theliquid to be purified in the manufacturing process of the chemicalliquid (for example, contamination), and the like.

(Resin)

The liquid to be purified may contain a resin. As the resin, a resin Phaving a group which is decomposed by the action of an acid andgenerates a polar group is preferable. As such a resin, a resin having arepeating unit represented by Formula (AI) that will be described lateris more preferable, which is a resin whose solubility in a developercontaining an organic solvent as a main component is reduced by theaction of an acid. The resin having a repeating unit represented byFormula (AI), which will be described later, has a group that isdecomposed by the action of an acid and generates an alkali-solublegroup (hereinafter, also referred to as an “acid-decomposable group”).

Examples of the polar group include an alkali-soluble group. Examples ofthe alkali-soluble group include a carboxy group, a fluorinated alcoholgroup (preferably a hexafluoroisopropanol group), a phenolic hydroxylgroup, and a sulfo group.

In the acid-decomposable group, the polar group is protected by a groupleaving by an acid (acid leaving group). Examples of the acid leavinggroup include —C(R₃₆)(R₃₇)(R₃₈), —C(R₃₆)(R₃₇)(OR₃₉), —C(R₀₁)(R₀₂)(OR₃₉),and the like.

In the formulas, R₃₆ to R₃₉ each independently represent an alkyl group,a cycloalkyl group, an aryl group, an aralkyl group, or an alkenylgroup. R₃₆ and R₃₇ may be bonded to each other to form a ring.

R₀₁ and R₀₂ each independently represent a hydrogen atom, an alkylgroup, a cycloalkyl group, an aryl group, an aralkyl group, or analkenyl group.

Hereinafter, the resin P whose solubility in a developer containing anorganic solvent as a main component is reduced by the action of an acidwill be specifically described.

(Formula (AI): repeating unit having acid-decomposable group)

It is preferable that the resin P contains a repeating unit representedby Formula (AI).

In Formula (AI),

Xa₁ represents a hydrogen atom or an alkyl group which may have asubstituent.

T represents a single bond or a divalent linking group.

Ra₁ to Ra₃ each independently represent an alkyl group (linear orbranched) or a cycloalkyl group (monocyclic or polycyclic).

Two out of Ra₁ to Ra₃ may be bonded to each other to form a cycloalkylgroup (monocyclic or polycyclic).

Examples of the alkyl group which is represented by Xa₁ and may have asubstituent include a methyl group and a group represented by —CH₂—R₁₁.R₁₁ represents a halogen atom (such as a fluorine atom), a hydroxylgroup, or a monovalent organic group.

Xa₁ is preferably a hydrogen atom, a methyl group, a trifluoromethylgroup, or a hydroxymethyl group.

Examples of the divalent linking group represented by T include analkylene group, a —COO-Rt- group, a —O-Rt- group, and the like. In theformulas, Rt represents an alkylene group or a cycloalkylene group.

T is preferably a single bond or a —COO-Rt- group. Rt is preferably analkylene group having 1 to 5 carbon atoms, and more preferably a —CH₂—group, a —(CH₂)₂— group, or a —(CH₂)₃— group.

The alkyl group represented by Ra₁ to Ra₃ preferably has 1 to 4 carbonatoms.

The cycloalkyl group represented by Ra₁ to Ra₃ is preferably amonocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexylgroup, or a polycyclic cycloalkyl group such as a norbornyl group, atetracyclodecanyl group, a tetracyclododecanyl group, or an adamantylgroup.

The cycloalkyl group formed by the bonding of two out of Ra₁ to Ra₃ ispreferably a monocyclic cycloalkyl group such as a cyclopentyl group ora cyclohexyl group, or a polycyclic cycloalkyl group such as a norbornylgroup, a tetracyclodecanyl group, a tetracyclododecanyl group, or anadamantyl group. Among these, a monocyclic cycloalkyl group having 5 or6 carbon atoms is more preferable.

In the cycloalkyl group formed by the bonding of two out of Ra₁ to Ra₃,for example, one of the methylene groups constituting a ring may besubstituted with a hetero atom such as an oxygen atom or with a grouphaving a hetero atom such as a carbonyl group.

As the repeating unit represented by Formula (AI), for example, anembodiment is preferable in which Ra₁ is a methyl group or an ethylgroup, and Ra₂ and Ra₃ are bonded to each other to form the cycloalkylgroup described above.

Each of the above groups may have a substituent. Examples of thesubstituent include an alkyl group (having 1 to 4 carbon atoms), ahalogen atom, a hydroxyl group, an alkoxy group (having 1 to 4 carbonatoms), a carboxy group, an alkoxycarbonyl group (having 2 to 6 carbonatoms), and the like. The number of carbon atoms in the substituent ispreferably equal to or smaller than 8.

The content of the repeating unit represented by Formula (AI) withrespect to all the repeating units in the resin P is preferably from 20to 90 mol %, more preferably from 25 to 85 mol %, and even morepreferably from 30 to 80 mol %.

(Repeating Unit Having Lactone Structure)

Furthermore, it is preferable that the resin P contains a repeating unitQ having a lactone structure.

The repeating unit Q having a lactone structure preferably has a lactonestructure on a side chain. The repeating unit Q is more preferably arepeating unit derived from a (meth)acrylic acid derivative monomer.

One kind of repeating unit Q having a lactone structure may be usedsingly, or two or more kinds of repeating units Q may be used incombination. However, it is preferable to use one kind of repeating unitQ singly.

The content of the repeating unit Q having a lactone structure withrespect to all the repeating units in the resin P is preferably 3 to 80mol %, and more preferably 3 to 60 mol %.

The lactone structure is preferably a 5- to 7-membered lactonestructure, and more preferably a structure in which another ringstructure is fused with a 5- to 7-membered lactone structure by forminga bicyclo structure or a spiro structure.

It is preferable that the lactone structure has a repeating unit havinga lactone structure represented by any of Formulas (LC1-1) to (LC1-17).The lactone structure is more preferably a lactone structure representedby Formula (LC1-1), Formula (LC1-4), Formula (LC-5), or Formula (LC-8),and even more preferably a lactone structure represented by Formula(LC1-4).

The lactone structure portion may have a substituent (Rb₂). As thesubstituent (Rb₂), for example, an alkyl group having 1 to 8 carbonatoms, a cycloalkyl group having 4 to 7 carbon atoms, an alkoxy grouphaving 1 to 8 carbon atoms, an alkoxycarbonyl group having 2 to 8 carbonatoms, a carboxy group, a halogen atom, a hydroxyl group, a cyano group,an acid-decomposable group, and the like are preferable. n₂ representsan integer of 0 to 4. In a case where n₂ is equal to or greater than 2,a plurality of substituents (Rb₂) may be the same as or different fromeach other, and the plurality of substituents (Rb₂) may be bonded toeach other to form a ring.

(Repeating Unit Having Phenolic Hydroxyl Group)

The resin P may also contain a repeating unit having a phenolic hydroxylgroup.

Examples of the repeating unit having a phenolic hydroxyl group includea repeating unit represented by General Formula (I).

In the formula,

R₄₁, R₄₂ and R₄₃ each independently represent a hydrogen atom, an alkylgroup, a halogen atom, a cyano group, or an alkoxycarbonyl group. Here,R₄₂ may be bonded to Ar₄ to form a ring, and in this case, R₄₂represents a single bond or an alkylene group.

X₄ represents a single bond, —COO—, or —CONR₆₄—, and R₆₄ represents ahydrogen atom or an alkyl group.

L₄ represents a single bond or an alkylene group.

Ar₄ represents an (n+1)-valent aromatic ring group. In a case where Ar₄is bonded to R₄₂ to form a ring, Ar₄ represents an (n+2)-valent aromaticring group.

n represents an integer of 1 to 5.

As the alkyl group represented by R₄₁, R₄₂, and R₄₃ in General Formula(I), an alkyl group having 20 or less carbon atoms, such as a methylgroup, an ethyl group, a propyl group, an isopropyl group, an n-butylgroup, a sec-butyl group, a hexyl group, a 2-ethylhexyl group, an octylgroup, or a dodecyl group which may have a substituent, is preferable,an alkyl group having 8 or less carbon atoms is more preferable, and analkyl group having 3 or less carbon atoms is even more preferable.

The cycloalkyl group represented by R₄₁, R₄₂, and R₄₃ in General Formula(I) may be monocyclic or polycyclic. The cycloalkyl group is preferablya monocyclic cycloalkyl group having 3 to 8 carbon atoms such as acyclopropyl group, a cyclopentyl group, or a cyclohexyl group which mayhave a substituent.

Examples of the halogen atom represented by R₄₁, R₄₂, and R₄₃ in GeneralFormula (I) include a fluorine atom, a chlorine atom, a bromine atom,and an iodine atom. Among these, a fluorine atom is preferable.

As the alkyl group included in the alkoxycarbonyl group represented byR₄₁, R₄₂, and R₄₃ in General Formula (I), the same alkyl group as thealkyl group represented by R₄₁, R₄₂, and R₄₃ described above ispreferable.

Examples of the substituent in each of the above groups include an alkylgroup, a cycloalkyl group, an aryl group, an amino group, an amidegroup, a ureido group, a urethane group, a hydroxy group, a carboxygroup, a halogen atom, an alkoxy group, a thioether group, an acylgroup, an acyloxy group, an alkoxycarbonyl group, a cyano group, a nitrogroup, and the like. The number of carbon atoms in the substituent ispreferably equal to or smaller than 8.

Ar₄ represents an (n+1)-valent aromatic ring group. In a case where n is1, the divalent aromatic ring group may have a substituent, and examplesthereof include arylene groups having 6 to 18 carbon atoms, such as aphenylene group, a tolylene group, a naphthylene group, and ananthracenylene group, and aromatic ring groups having a hetero ring suchas thiophene, furan, pyrrole, benzothiophene, benzofuran, benzopyrrole,triazine, imidazole, benzimidazole, triazole, thiadiazole, and thiazole.

In a case where n is an integer equal to or greater than 2, specificexamples of the (n+1)-valent aromatic ring group include groups obtainedby removing (n−1) pieces of any hydrogen atom from the aforementionedspecific examples of the divalent aromatic ring group.

The (n+1)-valent aromatic ring group may further have a substituent.

Examples of the substituent that the aforementioned alkyl group,cycloalkyl group, alkoxycarbonyl group, alkylene group, and (n+1)-valentaromatic ring group can have include the alkyl group exemplified aboveas R₄₁, R₄₂, and R₄₃ in General Formula (I); an alkoxy group such as amethoxy group, an ethoxy group, a hydroxyethoxy group, a propoxy group,a hydroxypropoxy group, and a butoxy group; and an aryl group such as aphenyl group.

Examples of the alkyl group represented by R₆₄ in —CONR₆₄— (R₆₄represents a hydrogen atom or an alkyl group) represented by X₄ includean alkyl group having 20 to or less carbon atoms, such as a methylgroup, an ethyl group, a propyl group, an isopropyl group, a n-butylgroup, a sec-butyl group, a hexyl group, a 2-ethylhexyl group, an octylgroup, and a dodecyl group which may have a substituent. Among these, analkyl group having 8 or less carbon atoms is more preferable.

X₄ is preferably a single bond, —COO— or —CONH—, and more preferably asingle bond or —COO—.

The alkylene group represented by L₄ is preferably an alkylene grouphaving 1 to 8 carbon atoms such as a methylene group, an ethylene group,a propylene group, a butylene group, a hexylene group, and an octylenegroup which may have a substituent.

Ar₄ is preferably an aromatic ring group having 6 to 18 carbon atomsthat may have a substituent, and more preferably a benzene ring group, anaphthalene ring group, or a biphenylene ring group.

It is preferable that the repeating unit represented by General Formula(I) comprises a hydroxystyrene structure. That is, Ar₄ is preferably abenzene ring group.

The content of the repeating unit having a phenolic hydroxyl group withrespect to all the repeating units in the resin P is preferably 0 to 50mol %, more preferably 0 to 45 mol %, and even more preferably 0 to 40mol %.

(Repeating Unit Containing Organic Group Having Polar Group)

The resin P may further contain a repeating unit containing an organicgroup having a polar group, particularly, a repeating unit having analicyclic hydrocarbon structure substituted with a polar group. In acase where the resin P further contains such a repeating unit, thesubstrate adhesion and the affinity with a developer are improved.

The alicyclic hydrocarbon structure substituted with a polar group ispreferably an adamantyl group, a diadamantyl group, or a norbornanegroup. As the polar group, a hydroxyl group or a cyano group ispreferable.

In a case where the resin P contains a repeating unit containing anorganic group having a polar group, the content of such a repeating unitwith respect to all the repeating units in the resin P is preferably 1to 50 mol %, more preferably 1 to 30 mol %, even more preferably 5 to 25mol %, and particularly preferably 5 to 20 mol %.

(Repeating Unit Represented by General Formula (VI))

The resin P may also contain a repeating unit represented by GeneralFormula (VI).

In General Formula (VI),

R₆₁, R₆₂, and R₆₃ each independently represent a hydrogen atom, an alkylgroup, a cycloalkyl group, a halogen atom, a cyano group, or analkoxycarbonyl group. Here, R₆₂ may be bonded to Ar₆ to form a ring, andin this case, R₆₂ represents a single bond or an alkylene group.

X₆ represents a single bond, —COO—, or —CONR₆₄—. R₆₄ represents ahydrogen atom or an alkyl group.

L₆ represents a single bond or an alkylene group.

Ar₆ represents an (n+1)-valent aromatic ring group. In a case where Ar₆is bonded to R₆₂ to form a ring, Ar₆ represents an (n+2)-valent aromaticring group.

In a case where n≥2, Y₂ each independently represents a hydrogen atom ora group which leaves by the action of an acid. Here, at least one ofY₂'s represents a group which leaves by the action of an acid.

n represents an integer of 1 to 4.

As the group Y₂ which leaves by the action of an acid, a structurerepresented by General Formula (VI-A) is preferable.

L₁ and L₂ each independently represent a hydrogen atom, an alkyl group,a cycloalkyl group, an aryl group, or a group obtained by combining analkylene group with an aryl group.

M represents a single bond or a divalent linking group.

Q represents an alkyl group, a cycloalkyl group which may have a heteroatom, an aryl group which may have a hetero atom, an amino group, anammonium group, a mercapto group, a cyano group, or an aldehyde group.

At least two out of Q, M and L₁ may be bonded to each other to form aring (preferably a 5- or 6-membered ring).

The repeating unit represented by General Formula (VI) is preferably arepeating unit represented by General Formula (3).

In General Formula (3),

Ar₃ represents an aromatic ring group.

R₃ represents a hydrogen atom, an alkyl group, a cycloalkyl group, anaryl group, an aralkyl group, an alkoxy group, an acyl group, or aheterocyclic group.

M₃ represents a single bond or a divalent linking group.

Q₃ represents an alkyl group, a cycloalkyl group, an aryl group, or aheterocyclic group.

At least two out of Q₃, M₃, and R₃ may be bonded to each other to form aring.

The aromatic ring group represented by Ar₃ is the same as Ar₆ in GeneralFormula (VI) in which n is 1. The aromatic ring group is preferably aphenylene group or a naphthylene group, and more preferably a phenylenegroup.

(Repeating Unit Having Silicon Atom on Side Chain)

The resin P may further contain a repeating unit having a silicon atomon a side chain. Examples of the repeating unit having a silicon atom ona side chain include a (meth)acrylate-based repeating unit having asilicon atom, a vinyl-based repeating unit having a silicon atom, andthe like. The repeating unit having a silicon atom on a side chain istypically a repeating unit having a group, which has a silicon atom, ona side chain. Examples of the group having a silicon atom include atrimethylsilyl group, a triethylsilyl group, a triphenylsilyl group, atricyclohexylsilyl group, a tristrimethylsiloxysilyl group, atristrimethylsilyl silyl group, a methyl bistrimethylsilyl silyl group,a methyl bistrimethylsiloxysilyl group, a dimethyltrimethylsilyl silylgroup, a dimethyl trimethylsiloxysilyl group, cyclic or linearpolysiloxane shown below, a cage-like, ladder-like, or randomsilsesquioxane structure, and the like. In the formula, R and R¹ eachindependently represent a monovalent substituent. * represents a bond.

As the repeating unit having the aforementioned group, for example, arepeating unit derived from an acrylate or methacrylate compound havingthe aforementioned group or a repeating unit derived from a compoundhaving the aforementioned group and a vinyl group is preferable.

In a case where the resin P has the repeating unit having a silicon atomon a side chain, the content of such a repeating unit with respect toall the repeating units in the resin P is preferably 1 to 30 mol %, morepreferably 5 to 25 mol %, and even more preferably 5 to 20 mol %.

The weight-average molecular weight of the resin P that is measured by agel permeation chromatography (GPC) method and expressed in terms ofpolystyrene is preferably 1,000 to 200,000, more preferably 3,000 to20,000, and even more preferably 5,000 to 15,000. In a case where theweight-average molecular weight is 1,000 to 200,000, it is possible toprevent the deterioration of heat resistance and dry etching resistance,to prevent the deterioration of developability, and to prevent filmforming properties from deteriorating due to the increase in viscosity.

The dispersity (molecular weight distribution) is generally 1 to 5,preferably 1 to 3, more preferably 1.2 to 3.0, and even more preferably1.2 to 2.0.

As other components (for example, an acid generator, a basic compound, aquencher, a hydrophobic resin, a surfactant, a solvent, and the like) tobe contained in the chemical liquid, any known components can be used.

<Aqueous Liquid to be Purified>

The aqueous liquid to be purified contains water in an amount greaterthan 50% by mass with respect to the total mass of solvents contained inthe aqueous liquid to be purified. The content of water is preferably51% to 95% by mass.

The water is not particularly limited, but it is preferable to useultrapure water used for manufacturing semiconductors. The ultrapurewater is more preferably used after being further purified such that theinorganic anions, metal ions, and the like are reduced. The purificationmethod is not particularly limited, but is preferably purification usinga filtration membrane or an ion-exchange membrane and purification bydistillation. Furthermore, for example, it is preferable to performpurification by the method described in JP2007-254168A.

(Oxidant)

The aqueous liquid to be purified may contain an oxidant. As theoxidant, known oxidants can be used without particular limitation.Examples of the oxidant include hydrogen peroxide, a peroxide, nitricacid, nitrate, iodate, periodate, hypochlorite, chlorite, chlorate,perchlorate, persulfate, dichromate, permanganate, aqueous ozone, asilver (II) salt, an iron (III) salt, and the like.

The content of the oxidant is not particularly limited, but ispreferably equal to or greater than 0.1% by mass and equal to or smallerthan 99% by mass with respect to the total mass of the aqueous liquid tobe purified. One kind of oxidant may be used singly, or two or morekinds of oxidants may be used in combination. In a case where two ormore kinds of oxidants are used in combination, the total contentthereof is preferably within the above range.

(Inorganic Acid)

The aqueous liquid to be purified may contain an inorganic acid. As theinorganic acid, known inorganic acids can be used without particularlimitation. Examples of the inorganic acid include sulfuric acid,phosphoric acid, hydrochloric acid, and the like. The inorganic acid isnot included in the oxidant described above.

The content of the inorganic acid in the aqueous liquid to be purifiedis not particularly limited, but is preferably equal to or greater than0.01% by mass and equal to or smaller than 99% by mass with respect tothe total mass of the aqueous liquid to be purified.

One kind of inorganic acid may be used singly, or two or more kinds ofinorganic acids may be used in combination. In a case where two or morekinds of inorganic acids are used in combination, the total contentthereof is preferably within the above range.

(Anticorrosive)

The aqueous liquid to be purified may contain an anticorrosive. As theanticorrosive, known anticorrosives can be used without particularlimitation. Examples of the anticorrosive include 1,2,4-triazole (TAZ),5-aminotetrazole (ATA), 5-amino-1,3,4-thiadiazole-2-thiol,3-amino-1H-1,2,4-triazole, 3,5-diamino-1,2,4-triazole, tolyl triazole,3-amino-5-mercapto-1,2,4-triazole, 1-amino-1,2,4-triazole,1-amino-1,2,3-triazole, 1-amino-5-methyl-1,2,3-triazole,3-mercapto-1,2,4-triazole, 3-isopropyl-1,2,4-triazole, naphthotriazole,1H-tetrazole-5-acetic acid, 2-mercaptobenzothiazole (2-MBT),1-phenyl-2-tetrazoline-5-thione, 2-mercaptobenzimidazole (2-MBI),4-methyl-2-phenylimidazole, 2-mercaptothiazoline,2,4-diamino-6-methyl-1,3,5-triazine, thiazole, imidazole, benzimidazole,triazine, methyl tetrazole, bismuthiol I,1,3-dimethyl-2-imidazolidinone, 1,5-pentamethylenetetrazole,1-phenyl-5-mercaptotetrazole, diaminomethyltriazine, imidazolinethion,4-methyl-4H-1,2,4-triazole-3-thiol, 5-amino-1,3,4-thiadiazole-2-thiol,benzothiazole, tritolyl phosphate, indazole, adenine, cytosine, guanine,thymine, a phosphate inhibitor, amines, pyrazoles, propanethiol,silanes, secondary amines, benzohydroxamic acids, a heterocyclicnitrogen inhibitor, thiourea, 1,1,3,3-tetramethylurea, urea, ureaderivatives, uric acid, potassium ethylxanthate, glycine, dodecylphosphate, iminodiacetic acid, boric acid, malonic acid, succinic acid,nitrilotriacetic acid, sulfolane, 2,3,5-trimethylpyrazine,2-ethyl-3,5-dimethylpyrazine, quinoxaline, acetylpyrrole, pyridazine,histadine, pyrazine, glutathione (reduced), cysteine, cystine,thiophene, mercaptopyridine N-oxide, thiamine HCl, tetraethylthiuramdisulfide, 2,5-dimercapto-1,3-thiadiazole ascorbic acid, catechol,t-butyl catechol, phenol, and pyrogallol.

As the anticorrosive, it is also possible to use aliphatic carboxylicacids such as dodecanoic acid, palmitic acid, 2-ethylhexanoic acid, andcyclohexanoic acid; carboxylic acids having a chelating ability such ascitric acid, malic acid, oxalic acid, malonic acid, succinic acid,itaconic acid, maleic acid, glycolic acid, mercaptoacetic acid,thioglycolic acid, salicylic acid, sulfosalicylic acid, anthranilicacid, N-methylanthranilic acid, 3-amino-2-naphthoic acid,1-amino-2-naphthoic acid, 2-amino-1-naphthoic acid,1-aminoanthraquinone-2-carboxylic acid, tannic acid, and gallic acid;and the like.

Examples of the anticorrosive also include anionic surfactants such as apalm fatty acid salt, a sulfonated castor oil salt, a lauryl sulfatesalt, a polyoxyalkylene allyl phenyl ether sulfate salt, alkylbenzenesulfonic acid, alkylbenzene sulfonate, alkyl diphenyl ether disulfonate,alkyl naphthalene sulfonate, a dialkylsulfosuccinate salt, isopropylphosphate, a polyoxyethylene alkyl ether phosphate salt, and apolyoxyethylene allyl phenyl ether phosphate salt; cationic surfactantssuch as oleylamine acetate, laurylpyridinium chloride, cetylpyridiniumchloride, lauryltrimethylammonium chloride, stearyltrimethylammoniumchloride, behenyltrimethylammonium chloride, and didecyldimethylammoniumchloride; amphoteric surfactants such as palm alkyldimethylamine oxide,fatty acid amidopropyldimethylamine oxide, alkylpolyaminoethyl glycinehydrochloride, an amidobetaine-type activator, an alanine-typeactivator, and lauryl iminodipropionic acid; nonionic surfactants of apolyoxyalkylene primary alkyl ether or a polyoxyalkylene secondary alkylether, such as polyoxyethylene octyl ether, polyoxyethylene decyl ether,polyoxyethylene lauryl ether, polyoxyethylene lauryl amine,polyoxyethylene oleyl amine, polyoxyethylene polystyryl phenyl ether,and polyoxyalkylene polystyryl phenyl ether and otherpolyoxyalkylene-based nonionic surfactants such as polyoxyethylenedilaurate, polyoxyethylene laurate, polyoxyethylated castor oil,polyoxyethylated hydrogenated castor oil, a sorbitan lauric acid ester,a polyoxyethylene sorbitan lauric acid ester, and fatty aciddiethanolamide; fatty acid alkyl esters such as octyl stearate andtrimethylolpropane tridecanoate; and polyether polyols such aspolyoxyalkylene butyl ether, polyoxyalkylene oleyl ether, andtrimethylolpropane tris(polyoxyalkylene) ether.

Examples of commercial products of the above anticorrosives includeNEWCALGEN FS-3PG (manufactured by TAKEMOTO OIL & FAT Co., Ltd.), PHOSTENHLP-1 (manufactured by Nikko Chemicals Co., Ltd.), and the like.

As the anticorrosive, a hydrophilic polymer can also be used.

Examples of the hydrophilic polymer include polyglycols such aspolyethylene glycol, an alkyl ether of polyglycols, polyvinyl alcohol,polyvinyl pyrrolidone, polysaccharides such as alginic acid, carboxylicacid-containing polymers such as polymethacrylic acid and polyacrylicacid, polyacrylamide, polymethacrylamide, polyethyleneimine, and thelike. Specific examples of these hydrophilic polymers include thewater-soluble polymers described in paragraphs “0042” to “0044” inJP2009-088243A and paragraph “0026” in JP2007-194261A.

As the anticorrosive, a cerium salt can also be used.

As the cerium salt, known cerium salts can be used without particularlimitation.

Examples of the cerium salt include trivalent cerium salts such ascerium acetate, cerium nitrate, cerium chloride, cerium carbonate,cerium oxalate, and cerium sulfate and tetravalent cerium salts such ascerium sulfate, cerium ammonium sulfate, cerium ammonium nitrate,diammonium cerium nitrate, cerium hydroxide, and the like.

The anticorrosive may include substituted or unsubstitutedbenzotriazole. Suitable substituted benzotriazole includes, but is notlimited to, benzotriazole substituted with an alkyl group, an arylgroup, a halogen group, an amino group, a nitro group, an alkoxy group,or a hydroxyl group. The substituted benzotriazole also includescompounds fused by one or more aryl (for example, phenyl) or heteroarylgroups.

The content of the anticorrosive in the aqueous liquid to be purifiedwith respect to the total mass of the chemical liquid is preferablyadjusted to 0.01% to 5% by mass, more preferably adjusted to 0.05% to 5%by mass, and even more preferably adjusted to 0.1% to 3% by mass.

One kind of anticorrosive may be used singly, or two or more kinds ofanticorrosives may be used in combination. In a case where two or morekinds of anticorrosives are used in combination, the total contentthereof is preferably within the above range.

(Organic Solvent)

The aqueous liquid to be purified may contain an organic solvent. Theorganic solvent is not particularly limited, and is the same as theaforementioned organic solvent contained in the organic solvent-basedliquid to be purified. In a case where the aqueous liquid to be purifiedcontains an organic solvent, the content of the organic solvent ispreferably 5% to 35% by mass with respect to the total mass of solventscontained in the aqueous liquid to be purified.

<Relationship Between Liquid to be Purified and Filtering Device>

The relationship between the liquid to be purified and the filteringdevice (arrangement of filters) is not particularly limited. Regardingthe relationship with the solubility parameter (SP value) of the liquidto be purified, in a case where the SP value is equal to or lower than20 (MPa)^(1/2), the filtering device preferably has the filter BU andthe filter A described above, and the filter BU more preferably containsa resin having an ion exchange group as a material component. The lowerlimit of the SP value is not particularly limited, but is preferablyequal to or higher than 14 (MPa)^(1/2).

According to the examination of the inventors of the present invention,it has been found that in a case where the SP value of the liquid to bepurified is equal to or lower than 20 (MPa)^(1/2), and the liquid to bepurified is passed through the filter BU containing a resin having anion exchange group as a material component, although the detailedmechanism is unclear, due to the swelling of the filter BU or the like,sometimes particle-like impurities including microgel-like substancesmigrate to the liquid to be purified from the filter BU.

In this case, the filter BU has a strong interaction with ioniccomponents (typically, impurities such as metal ions) in the liquid tobe purified, and thus can remove the impurities from the liquid to bepurified. On the other hand, as described above, in a case where the SPvalue of the liquid to be purified is equal to or lower than apredetermined range, sometimes a trace of impurities (including agel-like substance) are mixed into the liquid to be purified.

Conventionally, as one of the methods of removing such a gel-likesubstance from the liquid to be purified, adsorption by a nylon filterhas been exploited. However, in a case where the SP value of the liquidto be purified is equal to or smaller than 20 (MPa)^(1/2), thedurability of the nylon filter is insufficient, and sometimes the nylonfilter becomes a new source of defects.

In the filtering device according to the embodiment described above, thefilter A is disposed after the filter BU. Accordingly, the filteringdevice is preferable because the aforementioned particle-like impuritiesincluding the gel-like substance can be removed.

The filter A exhibits sufficient durability even for a liquid to bepurified having an SP value equal to or lower than 20 (MPa)^(1/2), andhas a hydrophilic surface. Presumably, for this reason, in a case wherethe liquid to be purified is passed through the filter A, a coating maybe formed on the surface of the membrane by a hydrophilic liquid, andthe gel-like impurities in the liquid to be purified could beefficiently removed by the coat.

In the present specification, the SP value means “value of thesolubility parameter”. The SP value mentioned in the present inventionis a Hansen solubility parameter determined by the equation explained in“Hansen Solubility Parameters: A User's Handbook, Second Edition, C. M.Hansen (2007), Taylor and Francis Group, LLC (HSPiP manual). As the SPvalue, a value calculated by the following equation by using “HansenSolubility Parameters in Practice HSPiP, 3rd Edition” (software version4. 0. 05) is used.(SP value)²=(δHd)²+(δHp)²+(δHh)²

Hd: dispersion element

Hp: polarization element (polarity element)

Hh: hydrogen bond element

In the case where the liquid to be purified is a mixture of two or morekinds of solvents, the SP value of the liquid to be purified isdetermined by the sum of the products of the SP value of each of thesolvents and the volume fraction of each of the solvents. That is, theSP value of the liquid to be purified it is represented by the followingequation.(SP value of liquid to be purified)=Σ{(SP value of each solvent)×(volumefraction of each solvent)}

For example, in a case where the solvent contained in the liquid to bepurified is a 7:3 (based on volume) mixture of PGMEA and PGME, the SPvalue thereof is calculated by 17.8×0.7+23.05×0.3, which equals 19.375(MPa)^(1/2). In the present specification, in a case where the SP valueis expressed by the unit of (MPa)^(1/2), the SP value is determined byrounding off the numbers to two decimal points. In the case describedabove, the SP value of the liquid to be purified is 19.4 (MPa)^(1/2) asdescribed in the tables in the following examples.

[Filtration Step]

The method for manufacturing a chemical liquid according to the presentembodiment includes a filtration step of filtering the liquid to bepurified by using the filtering device described above so as to obtain achemical liquid.

The filtering device has a flow path formed by arranging the filter Aand the filter B in series. The feed pressure of the liquid to bepurified supplied to each filter is not particularly limited, but ispreferably 0.00010 to 1.0 MPa in general.

Particularly, in view of obtaining a chemical liquid having furtherimproved defect inhibition performance, a feed pressure P₂ is preferably0.00050 to 0.090 MPa, more preferably 0.0010 to 0.050 MPa, and even morepreferably 0.0050 to 0.040 MPa.

The filtration pressure affects the filtration accuracy. Therefore, itis preferable that the pulsation of pressure during filtration is as lowas possible.

The filtration speed is not particularly limited. However, in view ofeasily obtaining a chemical liquid having further improved defectinhibition performance, the filtration speed is preferably equal to orhigher than 1.0 L/min/m², more preferably equal to or higher than 0.75L/min/m², and even more preferably equal to or higher than 0.6 L/min/m².

For the filter, an endurable differential pressure for assuring thefilter performance (assuring that the filter will not be broken) is set.In a case where the endurable differential pressure is high, byincreasing the filtration pressure, the filtration speed can beincreased. That is, it is preferable that the upper limit of thefiltration speed is generally equal to or lower than 10.0 L/min/m²although the upper limit usually depends on the endurable differentialpressure of the filter.

The temperature at which the liquid to be purified passes through thefilter is not particularly limited, but is preferably less than roomtemperature in general.

The filtration step is preferably performed in a clean environment.Specifically, the filtration step is preferably performed in a cleanroom that satisfies Class 1000 (Class 6 in ISO14644-1:2015) of FederalStandard (Fed. Std. 209E), more preferably performed in a clean roomthat satisfies Class 100 (Class 5 in ISO14644-1:2015), even morepreferably performed in a clean room that satisfies Class 10 (Class 4 inISO14644-1: 2015), and particularly preferably performed in a clean roomthat has a cleanliness (Class 2 or Class 1) equal to or higher thanClass 1 (Class 3 in ISO14644-1: 2015).

It is preferable that each step which will be described later is alsoperformed in the clean environment described above.

In a case where the filtering device has a return flow path, thefiltration step may be a circulation filtration step. The circulationfiltration step is a step of filtering the liquid to be purified by atleast the filter A, returning the liquid to be purified having beenfiltered through the filter A to the upstream of the filter A in theflow path, and filtering again the liquid to be purified through thefilter A.

The number of times of the circulation filtration is not particularlylimited, but is preferably 2 to 10 in general. During the circulationfiltration, the liquid to be purified may be returned to the upstream ofthe filter A such that the filtration by the filter A is repeated. Atthis time, the return flow path may be adjusted such that the filtrationby at least one filter B is also repeated in addition to the filtrationby the filter A.

[Other Steps]

The method for manufacturing a chemical liquid according to the presentembodiment may include steps other than the above step. Examples of thesteps other than the above step include a filter washing step, a devicewashing step, an electricity removing step, a step of preparing a liquidto be purified, and the like. Hereinafter, each of the steps will bespecifically described.

<Filter Washing Step>

The filter washing step is a step of washing the filter A and the filterB before the filtration step. The method of washing the filter is notparticularly limited, and examples thereof include a method of immersingthe filter in an immersion solution, a method of washing the filter bypassing a washing solution through the filter, a combination of these,and the like.

(Method of Immersing Filter in Immersion Solution)

Examples of the method of immersing the filter in the immersion solutioninclude a method of filling a container for immersion with the immersionsolution and immersing the filter in the immersion solution.

Immersion Solution

As the immersion solution, known immersion solutions can be used withoutparticular limitation. Particularly, in view of obtaining furtherimproved effects of the present invention, the immersion solutionpreferably contains water or an organic solvent as a main component, andmore preferably contains an organic solvent as a main component. In thepresent specification, the main component means a component of which thecontent is equal to or greater than 99.9% by mass with respect to thetotal mass of the immersion solution. The content of the main componentis preferably equal to or greater than 99.99% by mass.

The organic solvent is not particularly limited, and it is possible touse the organic solvent described above as the organic solvent containedin the liquid to be purified. Particularly, in view of obtaining furtherimproved effects of the present invention, it is preferable that theimmersion solution contains at least one kind of organic solventselected from the group consisting of an ester-based solvent and aketone-based solvent. Furthermore, these may be used in combination.

Examples of the ester-based solvent include, but are not limited to,ethyl acetate, methyl acetate, butyl acetate, sec-butyl acetate,methoxybutyl acetate, amyl acetate, normal propyl acetate, isopropylacetate, ethyl lactate, methyl lactate, butyl lactate, and the like.

Examples of the ketone-based solvent include, but are not limited to,acetone, 2-heptanone (MAK), methyl ethyl ketone (MEK), methyl isobutylketone, diisobutyl ketone, cyclohexanone, diacetone alcohol, and thelike.

The time for which the filter is immersed in the immersion solution isnot particularly limited. However, in view of obtaining further improvedeffects of the present invention, it is preferable that the filter isimmersed in the immersion solution for 7 days to 1 year.

The temperature of the immersion solution is not particularly limited.However, in view of obtaining further improved effects of the presentinvention, the temperature of the immersion solution is preferably equalto or higher than 20° C.

As the container for immersion, it is possible to use the housingstoring filters in the filtering device described above. That is, forexample, it is possible to use a method of filling the housing with theimmersion solution in a state where the filter (typically, a filtercartridge) is stored in the housing that the filtering device has andleaving the filter to stand still as it is.

In addition to the above method, for example, it is possible to use amethod of preparing a container for immersion in addition to the housingthat the filtering device has (that is, preparing a container forimmersion on the outside of the filtering device), filling theadditionally prepared container for immersion with the immersionsolution, and immersing the filter in the immersion solution.

Particularly, it is preferable to use a method of filling the containerfor immersion prepared on the outside of the filtering device with theimmersion solution and immersing the filter in the immersion solution,because then the impurities eluted from the filter are not mixed intothe filtering device.

The shape and size of the container for immersion are not particularlylimited and can be appropriately selected according to the number andsize of the filters to be immersed, and the like.

The material of the container for immersion is not particularly limited,and it is preferable that at least a liquid contact portion of thecontainer is formed of the anticorrosive material described above.

The container for immersion preferably contains, as a materialcomponent, at least one kind of material selected from the groupconsisting of polyfluorocarbon (such as PTFE, PFA: perfluoroalkoxyalkaneand PCTFE: polychlorotrifluoroethylene), PPS (polyphenylene sulfide),POM (polyoxymethylene), and polyolefin (PP and PE, etc.), morepreferably contains at least one kind of material selected from thegroup consisting of polyfluorocarbon, PPS, and POM, even more preferablycontains polyfluorocarbon, particularly preferably contains at least onekind of material selected from the group consisting of PTFE, PFA, andPCTFE, and most preferably contains PTFE.

Furthermore, it is preferable that the container for immersion is washedbefore use. During washing, it is preferable to perform washing(so-called pre-washing) by using the immersion solution.

(Method of Washing by Passing Washing Solution Through Filter)

The method of washing the filter by passing the washing solution throughthe filter is not particularly limited. For example, by storing thefilter (typically, a filter cartridge) in the filter housing of thefilter unit of the filtering device described above and introducing thewashing solution into the filter housing, the washing solution is passedthrough the filter.

During washing, the impurities having adhered to the filter migrate to(typically, dissolve in) the washing solution, and thus the content ofimpurities in the washing solution increases. Therefore, it ispreferable that the washing solution once passed through the filter isdischarged out of the filtering device without being reused for washing.In other words, it is preferable not to perform circulation washing.

As another form of the method of washing the filter by passing thewashing solution through the filter, for example, there is a method ofwashing the filter by using a washing device. In the presentspecification, the washing device means a device different from thefiltering device that is provided on the outside of the filteringdevice. Although the form of the washing device is not particularlylimited, it is possible to use a device having the same constitution asthat of the filtering device.

Washing Solution

As the washing solution which is used in a case where the filter iswashed by passing the washing solution through the filter, known washingsolutions can be used without particular limitation. Particularly, inview of obtaining further improved effects of the present invention, theform of the washing solution is preferably the same as that of theimmersion solution described above.

<Device Washing Step>

The device washing step is a step of washing the liquid contact portionof the filtering device before the filtration step. There is noparticular limitation on the method of washing the liquid contactportion of the filtering device before the filtration step. Hereinafter,a filtering device will be described for example in which a cartridgefilter is used as a filter and stored in a housing disposed on a flowpath.

It is preferable that the device washing step includes a step A ofwashing the liquid contact portion of the filtering device by using awashing solution in a state where the cartridge filter is detached fromthe housing, and a step B of storing the cartridge filter in the housingafter the step A and washing the liquid contact portion of the filteringdevice by using a washing solution.

Step A

The step A is a step of washing the liquid contact portion of thefiltering device by using a washing solution in a state where thecartridge filter is detached from the housing. “In a state where thefilter is detached from the housing” means that the liquid contactportion of the filtering device is washed using a washing solution afterthe filter cartridge is detached from the housing or before the filtercartridge is stored in the housing.

There is no particular limitation on the method of washing the liquidcontact portion of the filtering device by using a washing solution in astate where the filter is detached from the housing (hereinafter, alsodescribed as “filtering device not storing the filter”). Examplesthereof include a method of introducing the washing solution from theinlet portion and collecting the washing solution from the outletportion.

Particularly, in view of obtaining further improved effects of thepresent invention, examples of the method of washing the liquid contactportion of the filtering device not storing the filter by using awashing solution include a method of filling the filtering device notstoring the filter with a washing solution. In a case where thefiltering device not storing the filter is filled with a washingsolution, the liquid contact portion of the filtering device not storinga filter contacts the washing solution. As a result, impurities havingadhered to the liquid contact portion of the filtering device migrate to(typically, eluted in) the washing solution. After washing, the washingsolution may be discharged out of the filtering device (typically, thewashing solution may be discharged from the outlet portion).

Washing Solution

As the washing solution, known washing solutions can be used withoutparticular limitation. Particularly, in view of obtaining furtherimproved effects of the present invention, the washing solutionpreferably contains water or an organic solvent as a main component, andmore preferably contains an organic solvent as a main component. In thepresent specification, the main component means a component of which thecontent is equal to or greater than 99.9% by mass with respect to thetotal mass of the washing solution. The content of the main component ispreferably equal to or greater than 99.99% by mass.

The organic solvent is not particularly limited, and it is possible touse water and the organic solvent described above as the organic solventthat the chemical liquid contains. As the organic solvent, in view ofobtaining further improved effects of the present invention, at leastone kind of compound is preferable which is selected from the groupconsisting of PGMEA, cyclohexanone, ethyl lactate, butyl acetate, MIBC,MMP (3-methylmethoxypropionate), MAK, n-pentyl acetate, ethylene glycol,isopentyl acetate, PGME, methyl ethyl ketone (MEK), 1-hexanol, anddecane.

Step B

The step B is a method of washing the filtering device by using awashing solution in a state where a filter is stored in the housing.

As the method of washing the filtering device by using a washingsolution, in addition to the washing method in the step A describedabove, a method of passing a washing solution through the filteringdevice can also be used. The method of passing the washing solutionthrough the filtering device is not particularly limited. The washingsolution may be introduced from the inlet portion and discharged fromthe outlet portion. As the washing solution usable in this step, thewashing solution described in the step A can be used without particularlimitation.

<Electricity Removing Step>

The electricity removing step is a step of removing electricity from theliquid to be purified such that the charge potential of the liquid to bepurified is reduced. As the electricity removing method, knownelectricity removing methods can be used without particular limitation.Examples of the electricity removing method include a method of bringingthe liquid to be purified into contact with a conductive material.

The contact time for which the liquid to be purified is brought intocontact with a conductive material is preferably 0.001 to 60 seconds,more preferably 0.001 to 1 second, and even more preferably 0.01 to 0.1seconds. Examples of the conductive material include stainless steel,gold, platinum, diamond, glassy carbon, and the like.

Examples of the method of bringing the liquid to be purified intocontact with a conductive material include a method of disposing agrounded mesh consisting of a conductive material such that the meshcrosses the flow path and passing the liquid to be purified through themesh.

<Step of Preparing Liquid to be Purified>

The step of preparing a liquid to be purified is a step of preparing aliquid to be purified that will be caused to flow into the filteringdevice from the inlet portion of the filtering device. The method ofpreparing the liquid to be purified is not particularly limited.Typically, examples thereof include a method of purchasing commercialproducts (for example, those called “high-purity grade products”), amethod of reacting one kind or two or more kinds of raw materials so asto obtain a liquid to be purified, a method of dissolving components ina solvent, and the like.

As the method of obtaining a liquid to be purified (typically, a liquidto be purified containing an organic solvent) by reacting the rawmaterials, known methods can be used without particular limitation. Forexample, it is possible to use a method of reacting one or two or moreraw materials in the presence of a catalyst so as to obtain a liquid tobe purified containing an organic solvent.

More specifically, examples thereof include a method of obtaining butylacetate by reacting acetic acid and n-butanol in the presence ofsulfuric acid; a method of obtaining 1-hexanol by reacting ethylene,oxygen, and water in the presence of Al(C₂H)₃; a method of obtaining4-methyl-2-pentanol by reacting cis-4-methyl-2-pentene in the presenceof Diisopinocampheyl borane (Ipc₂BH); a method for obtaining propyleneglycol 1-monomethyl ether 2-acetate (PGMEA) by reacting propylene oxide,methanol and acetic acid in the presence of sulfuric acid; a method ofobtaining isopropyl alcohol (IPA) by reacting acetone and hydrogen inthe presence of copper oxide-zinc oxide-aluminum oxide; a method ofobtaining ethyl lactate by reacting lactic acid and ethanol; and thelike.

In addition, this step may have a pre-purification step of purifying theliquid to be purified in advance before the liquid is caused to flowinto the filtering device. The pre-purification step is not particularlylimited, and examples thereof include a method of purifying the liquidto be purified by using a distillation device.

In the pre-purification step, the method of purifying the liquid to bepurified by using a distillation device is not particularly limited.Examples thereof include a method of purifying the liquid to be purifiedin advance by using a distillation device prepared separately from thefiltering device so as to obtain a distilled liquid to be purified,storing the liquid in a portable tank, and transporting the tank to thefiltering device so as to introduce the liquid into the filteringdevice, and a method of using a purification device which will bedescribed later.

First, by using FIG. 11 , a method (pre-purification step) of purifyingthe liquid to be purified in advance by using a distillation deviceprepared separately from the filtering device will be described.

FIG. 11 is a schematic view showing the relationship between the devicesin a case where a chemical liquid is manufactured using a distilledliquid to be purified that is purified in advance by a distiller.

In FIG. 11 , the form of a filtering device 400 is the same as that ofthe filtering device according to the third embodiment of the presentinvention described above. Therefore, the filtering device 400 will notbe described.

In a chemical liquid manufacturing plant 1100, a filtering device 400and a distillation device 1101 are arranged. The distillation device1101 has a tank 401(a), a distiller 1102, and a portable tank 1103,which are connected to one another through a piping 1104 and a piping1105. The tank 401(a), the piping 1104, the distiller 1102, the piping1105, and the portable tank 1103 form a flow path S11.

The form of the tank 401(a) and each piping is not particularly limited,and it is possible to use the tank and piping of the same form asdescribed above as the tank and the piping included in the filteringdevice according to an embodiment of the present invention. As thedistiller 1102, it is possible to use the same distiller as thedistiller included in the purification device according to an embodimentof the present invention. The form of the distiller 1102 will bedescribed later.

In the distillation device 1101, a liquid to be purified introduced intothe tank 401(a) is distilled by the distiller 1102, and the obtaineddistilled liquid to be purified is stored in the portable tank 1103.Although the form of the portable tank is not particularly limited, itis preferable that at least a portion of the liquid contact portion ofthe tank (preferably 90% or more of the surface area of the liquidcontact portion and more preferably 99% or more of the surface area ofthe liquid contact portion) consists of the anticorrosive material whichwill be described later.

The distilled liquid to be purified stored in the portable tank 1103 istransported by a transporting unit 1106 (the flow of F1 in FIG. 11 ).Then, the distilled liquid to be purified is introduced into thefiltering device 400 from the inlet portion 101 of the filtering device.

In FIG. 11 , an embodiment is described in which a distillation deviceand a filtering device are arranged in the same manufacturing plant.However, the distillation device and the filtering device may bearranged in different manufacturing plants.

Next, a pre-purification step using a purification device having adistiller and a filtering device will be described. First, thepurification device used in this step will be described.

(Purification Device)

The purification device used in this step has the filtering devicedescribed above. The purification device according to an embodiment ofthe present invention has the filtering device described above, a secondinlet portion, a second outlet portion, and at least one distillerdisposed between the second inlet portion and the second outlet portion,in which the second outlet portion is connected to an inlet portion ofthe filtering device described above, and a flow path extending from thesecond inlet portion to the outlet portion of the filtering device isformed. Hereinafter, the purification device will be described withreference to drawings.

In the following section, the details relating to the constitution ofthe filtering device will not be described because they are the same asthose described above.

First Embodiment of Purification Device

FIG. 12 is a schematic view illustrating a first embodiment of thepurification device of the present invention. A purification device 1200has a second inlet portion 1201, a second outlet portion 1202, and adistiller 1203 disposed between the second inlet portion 1201 and thesecond outlet portion 1202, in which the second outlet portion 1202 isconnected to an inlet portion 101 of the filtering device. Therefore, inthe purification device 1200, by the second inlet portion 1201, thedistiller 1203, the second outlet portion 1202, the inlet portion 101,the filter 104 (filter BU), a piping 105, the filter 103 (filter A), andthe outlet portion 102, a flow path S12 is formed.

That is, the distiller 1203 is connected to the inlet portion 101 of thefiltering device 100.

The liquid to be purified having flowed into the purification device1200 from the second inlet portion 1201 is distilled in the distiller1203, and then is introduced into the filtering device 100 from theinlet portion 101 through the second outlet portion 1202. In a casewhere the pre-purification step is performed using the presentpurification device, the next step (filtration step) can be performedwithout discharging the distilled liquid to be purified outside thedevice. Therefore, a chemical liquid having further improved defectinhibition performance can be obtained.

The form of the distiller 1203 is not particularly limited, and knowndistillers (for example, a distillation column) can be used. As thematerial of the distiller 1203, it is possible to use the same materialas that of the housing described above. Particularly, it is preferablethat at least a portion of the liquid contact portion of the distiller1203 consists of the anticorrosive material which will be describedlater. It is preferable that 90% or more of the area of the liquidcontact portion consists of the anticorrosive material. It is morepreferable that 99% of the area of the liquid contact portion consistsof the anticorrosive material.

As the distiller, known distillers can be used without particularlimitation. The distiller may be a batch type or a continuous type, butis preferably a continuous type. Furthermore, the distiller may befilled with a filler. Although the form of the filler is notparticularly limited, it is preferable that at least a part of theliquid contact portion of the distiller consists of the anticorrosivematerial which will be described later. It is preferable that 90% ormore of the area of the liquid contact portion consists of theanticorrosive material. It is more preferable that 99% of the area ofthe liquid contact portion consists of the anticorrosive material.

In FIG. 12 , the purification device 1200 has a filtering device of anembodiment (for example, the first embodiment of the filtering device)in which the filter BU and the filter A are arranged in series in thisorder between the inlet portion and the outlet portion. However, insteadof this, the purification device may have a filtering device of anembodiment (for example, the second embodiment) in which the filter Aand the filter BD are arranged in series in this order between the inletportion and the outlet portion, and a filtering device of an embodiment(for example, a modification example of the second embodiment) in whichthe filter BU, the filter A, and the filter BD are arranged in series inthis order between the inlet portion and the outlet portion.

Furthermore, in the purification device, on the flow path S12 formed ofthe second inlet portion 1201, the distiller 1203, the second outletportion 1202, the inlet portion 101, the filter 104, the piping 105, thefilter 103, and the outlet portion 102, a return flow path may be formedwhich is capable of returning the liquid to be purified to the upstreamof the filter 103 (filter A) on the flow path S12 from the downstreamside of the filter 103 (filter A). The form of the return flow path isnot particularly limited, but is the same as that described in the fifthembodiment of the filtering device. In addition, the form of the returnflow path may be the same as that described in the sixth embodiment ofthe filtering device.

Furthermore, the purification device according to the present embodimentmay have a tank on the upstream side and/or the downstream side of thefilter 103 on the flow path S12. The form of the tank is notparticularly limited, and the same tank as that described above can beused.

Second Embodiment of Purification Device

FIG. 13 is a schematic view illustrating a second embodiment of thepurification device. A purification device 1300 has a second inletportion 1301, a second outlet portion 1302, and a distiller 1303 and adistiller 1304 arranged in series between the second inlet portion 1301and the second outlet portion 1302, in which the second outlet portion1302 is connected to an inlet portion 101 of the filtering device.Therefore, in the purification device 1300, by the second inlet portion1301, the distiller 1303, a piping 1305, the distiller 1304, the secondoutlet portion 1302, the inlet portion 101, the filter 104 (filter BU),the piping 105, the filter 103 (filter A), and the outlet portion 102, aflow path S13 is formed.

That is, the purification device according to the present embodimentincludes a plurality of distillers connected in series. In a case wherethe purification device includes three or more distillers connected inseries, the last distiller is connected to the filtering device.

In the purification device 1300, the liquid to be purified flowing fromthe second inlet portion 1301 is distilled by the distiller 1303, flowsthrough the piping 1305, and is introduced into the distiller 1304. FIG.13 shows an embodiment in which the distiller 1303 and the distiller1304 are connected to each other through the piping 1305. However, thepurification device according to the present embodiment is not limitedthereto, and may additionally have a piping capable of returning thecondensate of the distiller 1304 to the distiller 1303.

The purification device according to the present embodiment has twodistillers. Therefore, in a case where the operating conditions of thetwo distillers and the like are appropriately controlled, even thoughthe liquid to be purified contains two or more kinds of compounds havingdifferent boiling points, the target compound (chemical liquid) can bepurified to higher purity.

[Anticorrosive Material]

Next, an anticorrosive material will be described. In the filteringdevice and the purification device according to the embodiment of thepresent invention described so far, it is preferable that at least aportion of the liquid contact portion of the devices is formed of ananticorrosive material. It is preferable that 90% or more of the liquidcontact portion is formed of an anticorrosive material. It is morepreferable that 99% or more of the liquid contact portion is formed ofan anticorrosive material.

The state where the liquid contact portion is formed of an anticorrosivematerial is not particularly limited. Typically, for example, eachmember (for example, the tank described so far or the like) is formed ofan anticorrosive material, or each member has a base material and acoating layer which is disposed on the base material and formed of ananticorrosive material.

The anticorrosive material is a nonmetallic material or anelecltropolished metallic material. Examples of the nonmetallic materialinclude, but are not particularly limited to, a polyethylene resin, apolypropylene resin, a polyethylene-polypropylene resin, atetrafluoroethylene resin, a tetrafluoroethylene-perfluoroalkyl vinylether copolymer resin, a tetrafluoroethylene-hexafluoropropylenecopolymer resin, a tetrafluoroethylene-ethylene copolymer resin, achlorotrifluoro ethylene-ethylene copolymer resin, a vinylidene fluorideresin, a chlorotrifluoroethylene copolymer resin, a vinyl fluorideresin, and the like.

The metallic material is not particularly limited, and examples thereofinclude a metallic material in which the total content of Cr and Ni isgreater than 25% by mass with respect to the total mass of the metallicmaterial. The total content of Cr and Ni is particularly preferablyequal to or greater than 30% by mass. The upper limit of the totalcontent of Cr and Ni in the metallic material is not particularlylimited, but is preferably equal to or smaller than 90% by mass ingeneral

Examples of the metallic material include stainless steel, a Ni—Cralloy, and the like.

As the stainless steel, known stainless steel can be used withoutparticular limitation. Particularly, an alloy with a nickel contentequal to or greater than 8% by mass is preferable, and austenite-basedstainless steel with a nickel content equal to or greater than 8% bymass is more preferable. Examples of the austenite-based stainless steelinclude Steel Use Stainless (SUS) 304 (Ni content: 8% by mass, Crcontent: 18% by mass), SUS304L (Ni content: 9% by mass, Cr content: 18%by mass), SUS316 (Ni content: 10% by mass, Cr content: 16% by mass),SUS316L (Ni content: 12% by mass, Cr content: 16% by mass), and thelike.

As the Ni—Cr alloy, known Ni—Cr alloys can be used without particularlimitation. Particularly, a Ni—Cr alloy with a Ni content of 40% to 75%by mass and a Cr content of 1% to 30% by mass is preferable.

Examples of the Ni—Cr alloy include HASTELLOY (trade name, the same willbe applied hereinafter), MONEL (trade name, the same will be appliedhereinafter), INCONEL (trade name, the same will be appliedhereinafter), and the like. More specifically, examples thereof includeHASTELLOY C-276 (Ni content: 63% by mass, Cr content: 16% by mass),HASTELLOY C (Ni content: 60% by mass, Cr content: 17% by mass),HASTELLOY C-22 (Ni content: 61% by mass, Cr content: 22% by mass), andthe like.

Furthermore, optionally, the Ni—Cr alloy may further contain B, Si, W,Mo, Cu, Co, and the like in addition to the aforementioned alloy.

As the method for electropolishing the metallic material, known methodscan be used without particular limitation. For example, it is possibleto use the methods described in paragraphs “0011” to “0014” inJP2015-227501A, paragraphs “0036” to “0042” in JP2008-264929A, and thelike.

Presumably, in a case where the metallic material is electropolished,the Cr content in a passive layer on the surface thereof may becomehigher than the Cr content in the parent phase. Therefore, presumably,in a case where a purification device having a liquid contact portionformed of the elecltropolished metallic material is used, metalimpurities containing metal atoms may be hardly eluted into the liquidto be purified.

The metallic material may have undergone buffing. As the buffing method,known methods can be used without particular limitation. The size ofabrasive grains used for finishing the buffing is not particularlylimited, but is preferably equal to or smaller than #400 because suchgrains make it easy to further reduce the surface asperity of themetallic material. The buffing is preferably performed before theelectropolishing.

Method for Manufacturing Chemical Liquid (Second Embodiment)

The method for manufacturing a chemical liquid according to a secondembodiment of the present invention is a chemical liquid manufacturingmethod for obtaining a chemical liquid by purifying a liquid to bepurified, the method having a step of filtering a liquid to be purifiedby using a filter A having a porous base material made ofpolyfluorocarbon and a coating layer which is disposed to cover the basematerial and contains a resin having an adsorptive group and a filter Bdifferent from the filter A so as to obtain a chemical liquid.

Hereinafter, the method for manufacturing a chemical liquid according tothe second embodiment will be described. In the following section, thematerials, methods, conditions, and the like which are not described arethe same as those in the method for manufacturing a chemical liquidaccording to the first embodiment.

In the method for manufacturing a chemical liquid according to thepresent embodiment, the liquid to be purified is filtered using thefilter A and the filter B different from the filter A. In a case wherethe liquid to be purified is filtered, the liquid may be passed throughthe filter A and the filter B in this order, or may be passed throughthe filter B and the filter A in this order.

The method for manufacturing a chemical liquid according to the presentembodiment is not particularly limited as long as the filter A and thefilter B are used. In this method, the liquid to be purified may befiltered by sequentially using a plurality of filters A and/or aplurality of filters B.

In a case where the filter B and the filter A are used in this order,the form of the filter B is not particularly limited, but it ispreferable to use the filter described above as the filter BU. In a casewhere filter A and the filter B are used in this order, the form of thefilter B is not particularly limited, but it is preferable to use thefilter described above as the filter BD.

[Chemical Liquid]

It is preferable that the chemical liquid manufactured using theaforementioned filtering device is used for manufacturing asemiconductor substrate. Particularly, it is more preferable to use thechemical liquid for forming a fine pattern at a node equal to or smallerthan 10 nm (for example, a step including pattern formation usingextreme ultraviolet).

In other words, the filtering device is preferably used formanufacturing a chemical liquid for manufacturing a semiconductorsubstrate. Specifically, the filtering device is preferably used formanufacturing a chemical liquid used for treating an inorganic substanceand/or an organic substance after each step is finished or before thenext step is started in a semiconductor device manufacturing processincluding a lithography step, an etching step, an ion implantation step,a peeling step, and the like.

Specifically, the filtering device is preferably used for manufacturingat least one kind of chemical liquid (chemical liquid obtained bypurifying an organic liquid to be purified) selected from the groupconsisting of a developer, a rinsing solution, a wafer washing solution,a line washing solution, a prewet solution, a wafer rinsing solution, aresist solution, a solution for forming an underlayer film, a solutionfor forming an overlayer film, and a solution for forming a hardcoat. Inanother embodiment, the filtering device is preferably used formanufacturing at least one kind of chemical liquid (chemical liquidobtained by purifying an aqueous liquid to be purified) selected fromthe group consisting of an aqueous developer, an aqueous rinsingsolution, a peeling solution, a remover, an etching solution, an acidicwashing solution, phosphoric acid, and a phosphoric acid-aqueoushydrogen peroxide mixture (Sulfuric acid-Hydrogen Peroxide Mixture(SPM)).

In addition, the aforementioned filtering device can also be used formanufacturing a chemical liquid used for rinsing the edge line of asemiconductor substrate before and after the coating with resist.

Furthermore, the aforementioned filtering device can also be used formanufacturing a diluted solution of a resin contained in a resistsolution and for manufacturing a solvent contained in a resist solution.

In addition, the aforementioned filtering device can be used formanufacturing a chemical liquid used for purposes other than themanufacturing of a semiconductor substrate. The filtering device canalso be used for manufacturing a developer for polyimide, a resist forsensor, and a resist for lens, a rinsing solution, and the like.

Moreover, the filtering device can be used for manufacturing a solventfor medical uses or for washing. Particularly, the filtering device canbe used for manufacturing a chemical liquid used for washing containers,piping, base substrates (for example, a wafer and glass), and the like.

Especially, the filtering device is preferably used for manufacturing atleast one kind of chemical liquid selected from the group consisting ofa prewet solution, a developer, and a rinsing solution for forming apattern by using extreme ultraviolet (EUV).

[Chemical Liquid Storage Body]

The chemical liquid manufactured by the filtering device may be storedin a container and preserved until the chemical liquid is used. Thecontainer and the chemical liquid stored in the container arecollectively referred to as chemical liquid storage body. The preservedchemical liquid is used after being taken out of the chemical liquidstorage body.

As a container for preserving the chemical liquid, it is preferable touse a container for semiconductor substrate manufacturing, which has ahigh internal cleanliness and hardly causes the eluate of impuritiesinto the chemical liquid during the preservation of the chemical liquid.

Examples of usable containers include, but are not limited to, a “CLEANBOTTLE” series manufactured by AICELLO CORPORATION, “PURE BOTTLE”manufactured by KODAMA PLASTICS Co., Ltd., and the like.

As the container, for the purpose of preventing mixing of impuritiesinto the chemical liquid (contamination), it is also preferable to use amultilayer bottle in which the inner wall of the container has a 6-layerstructure formed of 6 kinds of resins or a multilayer bottle having a7-layer structure formed of 6 kinds of resins. Examples of thesecontainers include the containers described in JP2015-12335A.

It is preferable that at least a portion of the liquid contact portionof the container consists of the anticorrosive material described above.In view of obtaining further improved effects of the present invention,it is preferable that 90% or more of the area of the liquid contactportion consists of the material described above.

EXAMPLES

Hereinafter, the present invention will be more specifically describedbased on examples. The materials, the amount and proportion thereofused, the details of treatments, the procedure of treatments, and thelike shown in the following examples can be appropriately modified aslong as the gist of the present invention is maintained. Accordingly,the scope of the present invention is not limited to the followingexamples.

For preparing chemical liquids of examples and comparative examples, thehandling of containers, the preparation of chemical liquids, filling,preservation, and analytical measurement were all performed in a cleanroom of a level satisfying ISO class 2 or 1. In order to improve themeasurement accuracy, in the process of measuring the content of theorganic impurities and the content of metal atoms, in a case where thecontent of the organic impurities or metal atoms was found to be equalto or smaller than a detection limit by general measurement, thechemical liquid was concentrated by 1/100 in terms of volume forperforming the measurement, and the content was calculated by convertingthe concentration into the concentration of the chemical liquid not yetbeing concentrated. The tools such as a device or a filter used forpurification and a container were used after the surface contacting thechemical liquid was thoroughly washed with a chemical liquid purified inadvance by the same method.

Test Example 1: Purification of Organic Solvent-Based Liquid to bePurified and Performance Evaluation of Chemical Liquid

[Manufacturing of Chemical Liquid 1]

A chemical liquid 1 was manufactured using the purification device shownin FIG. 14 . The purification device in FIG. 14 has, between an inletportion and an outlet portion, a filtering device including a filterBU-1, a tank TU-1, a filter BU-2, a filter F-A, a filter BD-1, a tankTD-1, and a filter BD-2 that are connected in series and a distillerconnected to the front portion of the filtering device (duplex distillerconsisting of D1 and D2, described as “duplex” in the following tables).Each of the units forms a flow path S-14 together with the piping. Inthe flow path S-14, a return flow path R-14 is formed which is capableof returning the liquid to be purified to the upstream side of thefilter F-A from the downstream side (tank TD-1) of the filter F-A in theflow path S-14 (the filter F-A corresponds to the filter A describedabove).

The tables show the material components contained in the filters usedfor manufacturing the chemical liquid 1 and the pore size of thefilters. The filters were used after being immersed in PGMEA for oneday.

Abbreviations for the material components of each filter in the tablesare as follows.

PTFE-1

“PTFE-1” means a filter manufactured by the following method.

In a 50 ml round bottom flask equipped with a stirring bar, the secondgeneration Grubbs catalyst (3.0 mg, 0.004 mmol), 2-butene-1,4-diol (10.0mg, 0.12 mmol), and 1,5-cyclooctadiene (490 mg, 4.54 mmol) were mixedtogether, degassed with argon for 5 minutes, and transferred to an oilbath at 40° C. The mixture was kept heated for 1 hour, the residual1,5-cyclooctadiene (4.5 mg, 4.2 mmol) in 5 ml of a DCM solution wasadded to the mixture and kept heated for 6 more hours. Thehydroxyl-terminated polymer (P-COD) was isolated by precipitation inmethanol. ¹H-NMR (300 MHz, CDCl₃): δ (ppm) 5.3 to 5.5 (s, broad, 1H),1.75 to 2.5 (s, broad).

The P-COD homopolymer was post-functionalized with 1H,1H,2H,2H-perfluorodecanethiol in the presence of a photoinitiator under UVirradiation, thereby obtaining a fluorinated P-COD.

The PTFE porous membrane was immersed in a solution containing thefluorinated P-COD (concentration: 1% to 10% by mass) in a THF solution,a photoinitiator (Irgacure, 1% to 15% by mass), and sodium3-mercaptoethane sulfonate (1% to 15% by mass, neutralized using anaqueous solution of THF and dilute hydrochloric acid (1N) until ahomogeneous THF solution is obtained) such that the membrane wasmodified through a thiol-ene reaction. In this way, a membrane coatedwith fluorinated P-COD was obtained. Then, the membrane was irradiatedwith UV (300 to 480 nm, 150 to 250 mW, 60 seconds to 180 seconds) suchthat the membrane was crosslinked with the mixture of the solutiondescribed above. Thereafter, the membrane was washed with DI water anddried at 100° C. for 10 minutes.

PTFE-1 obtained by the above method had a porous base material made ofPTFE and a coating layer which was disposed to cover the porous basematerial and made of a copolymer having P-COD as a main chain and agroup having a thioether group as an adsorptive group(—SCH₂CH₂(CF₂)₇CF₃).

PTFE-2

“PTFE-2” means a filter manufactured by the following method.

With reference to the description in paragraphs “0018” to “0032” ofJP2017-002273A, a coating resin was obtained which had a carboxylic acidgroup introduced into the side chain through a thiol-ene reactionbetween mercaptoacetic acid and an allyl group. Furthermore, withreference to the description in paragraphs “0070” and “0071” ofJP2017-002273A, a coating layer made of the above resin was formed onthe PTFE porous membrane.

PTFE-2 obtained by the above method had a porous base material made ofPTFE and a coating layer which was disposed to cover the porous basematerial and made of a copolymer represented by Formula (I) having agroup that had a thioether group and a carboxylic acid group as anadsorptive group (—SCH₂COOH).

PTFE-3

“PTFE-3” means a filter manufactured by the following method.

With reference to the description in paragraphs “0018” to “0032” ofJP2017-002273A, a coating resin was obtained into which an aminoethylgroup was introduced through a thiol-ene reaction between mercaptoethyldiethylamine and an allyl group and then a quaternary ammonium group wasintroduced into the side chain through a quaternization reaction usingethyl bromide. Furthermore, with reference to the description inparagraphs “0070” and “0071” of JP2017-002273A, a coating layer made ofthe above resin was formed on the PTFE porous membrane.

PTFE-3 obtained by the above method had a porous base material made ofPTFE and a coating layer which was disposed to cover the porous basematerial and made of a copolymer represented by Formula (I) having agroup that had a thioether group and a quaternary ammonium group as anadsorptive group.

PTFE-4

“PTFE-4” means a filter manufactured by the following method.

With reference to the description in paragraphs “0018” to “0032” ofJP2017-002273A, a coating resin was obtained into which a thioethergroup was introduced through a thiol-ene reaction between2-ethylhexylthiopropyl mercaptan and an allyl group. With reference tothe description in paragraphs “0070” and “0071” of JP2017-002273A, acoating layer made of the above resin was formed on the PTFE porousmembrane.

PTFE-4 obtained by the above method had a porous base material made ofPTFE and a coating layer which was disposed to cover the porous basematerial and made of a copolymer represented by Formula (I) having agroup that had a group having a thioether group as an adsorptive group.

PTFE-5

“PTFE-5” means a filter manufactured by the following method.

With reference to the description in paragraphs “0018” to “0032” ofJP2017-002273A, a coating resin was obtained into which a phosphoricoxygroup was introduced through a thiol-ene reaction betweentripropyloxyphosphoric oxypropyl mercaptan and an allyl group. Withreference to the description in paragraphs “0070” and “0071” ofJP2017-002273A, a coating layer made of the above resin was formed onthe PTFE porous membrane.

PTFE-5 obtained by the above method had a porous base material made ofPTFE and a coating layer which was disposed to cover the porous basematerial and made of a copolymer represented by Formula (I) having agroup that had a thioether group and a phosphoric acid group as anadsorptive group.

PTFE-6

“PTFE-6” means a filter prepared by the following method.

With reference to the description in paragraphs “0068” to “0082” ofJP2016-029146A, a PTFE porous substance was obtained which was bonded toperfluorodecanethiol and coated with PFDT-PG-AGE.

PTFE-6 obtained by the above method had a porous base material made ofPTFE and a coating layer which was disposed to cover the porous basematerial and made of a copolymer as a fluorinated polymer having thestructure of “PFDT-PG-AGE” having a group having a thioether group as anadsorptive group.

PTFE-7

“PTFE-7” means a filter manufactured by the following method.

With reference to the description in paragraphs “0085” to “0088” ofJP2016-194040A, a PTFE porous membrane coated with poly(SZNB-b-NPF6)-2was obtained.

PTFE-7 obtained by the above method had a porous base material made ofPTFE and a coating layer which was disposed to cover the porous basematerial and made of a copolymer as a fluorinated polymer having thestructure of “poly(SZNB-b-NPF6)-2” having a group that had a sulfonicacid group and a quaternary ammonium group as an adsorptive group.

PTFE-8

“PTFE-8” means a filter manufactured by the following method.

With reference to the description in paragraphs “0110” to “0112” ofJP2016-196625A, poly(C2 diacid-r-NPF6) was synthesized. Furthermore,with reference to paragraph “0109” of JP2016-196625A, a coating layerwas formed on the PTFE porous membrane.

PTFE-8 obtained by the above method had a porous base material made ofPTFE and a coating layer which was disposed to cover the porous basematerial and made of a copolymer having the structure of “poly(C2diacid-r-NPF6)” and a group that had a carboxylic acid group and anoxyalkylene group as an adsorptive group.

PTFE-9

“PTFE-9” means a filter manufactured by the following method.

With reference to the description in paragraphs “0120” to “0124” ofJP2016-196625A, poly(C4-r-NPF6-r-NHS) was synthesized. Furthermore, withreference to paragraph “0109” of JP2016-196625A, a coating layer wasformed on the PTFE porous membrane.

¹H-NMR (300 MHz, CDCl₃): δ (ppm) 6 (s broad), 5.9 to 5.0 (m broad), 5.1to 4.6 (m broad), 4.6 to 4.1 (m broad), 4.0 to 3.0 (m broad), 3.0 to 2.4(m broad), 2.3 to 1.4 (m broad), 1.25 (s broad).

PTFE-9 obtained by the above method had a porous base material made ofPTFE and a coating layer which was disposed to cover the porous basematerial and made of a copolymer having the structure of“poly(C4-r-NPF6-r-NHS)” and a group that had a thioether group and adiester group as an adsorptive group.

-   -   PP: polypropylene    -   IEX: a filter obtained by introducing an ion exchange group        consisting of a sulfonic acid group into a base material made of        polyethylene.    -   Nylon: nylon    -   UPE: ultra-high-molecular-weight polyethylene    -   PTFE: polytetrafluoroethylene    -   HDPE: high-density polyethylene

Abbreviations relating to the liquid to be purified in Table 1 are asfollows.

-   -   CHN: cyclohexanone    -   PGMEA/PGME (7:3): a mixture of PGMEA and PGME at a ratio of 7:3        (based on volume)    -   nBA: butyl acetate    -   PC/PGMEA (1:9): a mixture of PC and PGMEA at a ratio of 1:9        (based on volume)    -   EL: ethyl lactate    -   MIBC: 4-methyl-2-pentanol    -   PGME: propylene glycol monoethyl ether    -   PGMEA: propylene glycol monomethyl ether acetate    -   PC: propylene carbonate    -   iAA: isoamyl acetate    -   IPA: isopropanol

A commercial high-purity grade “cyclohexanone” was purchased as theliquid to be purified, and purified using the purification devicedescribed above. For purification, circulation filtration was performedthree times by using the return flow path R-14, thereby obtaining achemical liquid 1.

[Manufacturing of Chemical Liquids 2 to 68]

Each of the liquids to be purified described in the table was purifiedusing a purification device (or a filtering device) described in thetable, thereby obtaining chemical liquids. The purification devices (orfiltering devices) are shown in FIGS. 14 to 31 . The material componentscontained in the filter F-A, the filters BU-1 to BU-3, and the filtersBD-1 and BD-2, and the pore sizes of the filters are as shown in thetable. During the purification of the liquid to be purified, a liquidthat was filtered using a filtering device, in which a return flow pathrepresented by R-(number) was formed, and described as “performed” inthe column of “Circulation” in the table was subjected to circulationfiltration three times through each return flow path.

In addition, the SP value of each of the liquids to be purified is alsodescribed in the table. In the table, “−” means that the filter was notused. The same is true of other tables in the present specification.

In the column of “Pre-washing of filter” in the table, the conditions ofpre-washing for each filter are described. “PGMEA 1 day immersion” meansthat the filter was used after being immersed for 1 day in high-puritygrade PGMEA. In addition, “-” in the same column shows that the filterwas not pre-washed.

[Evaluation 1: Evaluation of Residue Defect Inhibition Performance andStain-Like Defect Inhibition Performance of Chemical Liquid]

A silicon wafer (Bare-Si) having a diameter of about 300 mm was coatedwith the chemical liquid 1, thereby obtaining a wafer coated with achemical liquid. The used device was Lithius ProZ, and the coatingconditions were as follows.

-   -   Amount of chemical liquid used for coating: 2 ml    -   Rotation speed of silicon wafer during coating: 2,200 rpm, 60        sec

Then, by using a wafer inspection device “SP-5” manufactured byKLA-Tencor Corporation. and a fully automatic defectreview/classification device “SEMVision G6” manufactured by AppliedMaterials, Inc, the number of defects having a size equal to or greaterthan 19 nm existing on the entire surface of the wafer and thecomposition of the defects were investigated.

The total number of defects measured using SP-5 was counted as thenumber of residue defects, and the shape of the defects was observedusing G6. The (stain-like) defects that were not in the form ofparticles were counted as stain-like defects. The results were evaluatedbased on the following standard. The evaluation results are shown in thetable.

The smaller the number of defects present on the wafer, the better thedefect inhibition performance of the chemical liquid. In the followingevaluation, “number of defects” means the total number of residuedefects and stain-like defects. The chemical liquids 2 to 68 wereevaluated by the same method as the above method. The results are shownin the table.

AA The number of defects was equal to or smaller than 30/wafer.

A The number of defects was greater than 30/wafer and equal to orsmaller than 50/wafer.

B The number of defects was greater than 50/wafer and equal to orsmaller than 100/wafer

C The number of defects was greater than 100/wafer and equal to orsmaller than 200/wafer.

D The number of defects was greater than 200/wafer and equal to orsmaller than 500/wafer.

E The number of defects was greater than 500/wafer.

[Evaluation 2: Bridge Defect Inhibition Performance]

By using the chemical liquid 1 as a prewet solution, the bridge defectinhibition performance of the chemical liquid was evaluated. First, aresist resin composition used will be described.

Resist Resin Composition

The resist resin composition was obtained by mixing together thefollowing components.

Acid-decomposable resin (resin represented by the following formula(weight-average molecular weight (Mw) 7500): the numerical valuedescribed in each repeating unit means mol %): 100 parts by mass

The following photoacid generator: 8 parts by mass

The following quencher: 5 parts by mass (the mass ratio was0.1:0.3:0.3:0.2 in this order from the left). Among the followingquenchers, a polymer-type quencher has a weight-average molecular weight(Mw) of 5,000. The numerical value described in each repeating unitmeans molar ratio.

Hydrophobic resins shown below: 4 parts by mass (mass ratio:(1):(2)=0.5:0.5). Among the following hydrophobic resins, thehydrophobic resin represented by Formula (1) has a weight-averagemolecular weight (Mw) of 7,000, and the hydrophobic resin represented byFormula (2) has a weight-average molecular weight (Mw) of 8,000. In eachof the hydrophobic resins, the numerical value described in eachrepeating unit means molar ratio.

Solvent:

PGMEA (propylene glycol monomethyl ether acetate): 3 parts by mass

Cyclohexanone: 600 parts by mass

γ-BL (γ-butyrolactone): 100 parts by mass

Test Method

Next, the test method will be described. First, a silicon wafer having adiameter of about 300 mm was pre-wet with the chemical liquid 1, andthen the pre-wet silicon wafer was spin-coated with the resist resincomposition described above. Thereafter, the wafer was heated and driedat 150° C. for 90 seconds on a hot plate, thereby forming a resist filmhaving a thickness of 9 μm.

For the resist film, in order that a pattern having a line width of 30nm and a space width of 30 nm was formed after reduction projectionexposure and development, by using an ArF excimer laser scanner(manufactured by ASML, PAS5500/850C, wavelength: 248 nm), patternexposure was performed under the exposure conditions of NA=0.60 andσ=0.75 through a mask having a line-and-space pattern. After beingirradiated, the resist film was baked for 60 seconds at 120° C.Subsequently, the resist film was developed, rinsed, and then baked for60 seconds at 110° C., thereby forming a resist pattern having a linewidth of 30 nm and a space width of 30 nm.

By using a critical dimension SEM (CG4600, manufactured by HitachiHigh-Technologies Corporation), 100 shots of the resist pattern werecaptured. The number of defects in the form of a crosslink betweenpatterns (bridge defects) was counted, and the number of defects perunit area was determined. The results were evaluated based on thefollowing standard. The evaluation results are shown in the table. Notethat the smaller the number of defects in the form of a crosslinkbetween patterns, the better the bridge defect inhibition performance ofthe chemical liquid.

For the chemical liquids 2 to 68, those described as “Pre-wetting” inthe column of “Evaluation method” in the table were evaluated in termsof the bridge defect inhibition performance by the same method as thatused for the chemical liquid 1. The chemical liquids described as“Developer” in the column of “Evaluation method” in the table wereevaluated in terms of the bridge defect inhibition performance accordingto the same procedure as that used for evaluating the chemical liquid 1,except that the chemical liquids were not subjected to pre-wettingdescribed in the procedure for evaluating the chemical liquid 1, and thechemical liquids described in the table were used as a developer. Thechemical liquids described as “Rinsing” in the column of “Evaluationmethod” in the table were evaluated in terms of the bridge defectinhibition performance according to the same procedure as that used forevaluating the chemical liquid 1, except that the chemical liquids werenot subjected to pre-wetting described in the procedure for evaluatingthe chemical liquid 1, and the chemical liquids described in the tablewere used as a rinsing solution. The results are shown in the table.

AA The number of bridge defects was less than 1/cm².

A The number of bridge defects was equal to or greater than 1/cm² andless than 2/cm².

B The number of bridge defects was equal to or greater than 2/cm² andless than 5/cm².

C The number of bridge defects was equal to or greater than 5/cm² andless than 10/cm².

D The number of bridge defects was equal to or greater than 10/cm² andless than 15/cm².

E The number of bridge defects was equal to or greater than 15/cm².

[Evaluation 3: Uniformity of Pattern Width]

By using a critical dimension SEM (CG4600, manufactured by HitachiHigh-Technologies Corporation), 100 shots of the resist pattern werecaptured, and the absolute value of a difference between an average LineWidth Roughness (LWR) and a maximum (or minimum) line width wasdetermined. The results were evaluated based on the following standard.The evaluation results are shown in the table. Note that the smaller the“absolute value of difference”, the better the uniformity of the patternwidth formed using the chemical liquid. “Absolute value of thedifference between the average line width and the maximum (minimum) linewidth” means that between the difference between the average LWR and themaximum line width and the difference between the average LWR and theminimum line width, the larger one in terms of absolute value was usedto evaluate the pattern width uniformity.

AA The absolute value of a difference between the average line width andthe maximum (minimum) line width was less than 2% with respect to theaverage.

A The absolute value of a difference between the average line width andthe maximum (minimum) line width was equal to or greater than 2% andless than 5% with respect to the average.

B The absolute value of a difference between the average line width andthe maximum (minimum) line width was equal to or greater than 5% andless than 10% with respect to the average.

C The absolute value of a difference between the average line width andthe maximum (minimum) line width was equal to or greater than 10% andless than 20% with respect to the average.

D The absolute value of a difference between the average line width andthe maximum (minimum) line width was equal to or greater than 20% withrespect to the average.

E The line width could not be measured in some of the shots.

[Evaluation 4: Evaluation of Pot Life of Filter]

The liquid to be purified was continuously purified using each of thepurification devices (or filtering devices) described in the table.After the liquid to be purified was passed and the purification device(or filtering device) was stabilized, the obtained chemical liquid wasimmediately collected for test (initial sample). Then, whenever theamount of the liquid passing through the device became 10,000 kg, achemical liquid obtained after purification was collected for test(temporal sample). The chemical liquid collected for test was evaluatedby the method for evaluating the residue defect inhibition performanceof a chemical liquid described in “Evaluation 1”, and the number ofdefects per unit area was compared with that of the initial sample. Theamount of the chemical liquid passing the device that was determined ata point in time when the number of defects in the temporal sampledoubled was adopted as “pot life” of the filter. The pot life obtainedin a case where the filtering device described in FIG. 24 was used wasregarded as 1, and the pot life of the filter of each device wasevaluated based on a ratio to 1. The results were evaluated based on thefollowing standard. The evaluation results are shown in the table. Theevaluation result obtained using the device in FIG. 24 is described as“Standard”.

AA The pot life was equal to or longer than 10.

A The pot life was equal to or longer than 5 and less than 10.

B The pot life was equal to or longer than 2 and less than 5.

C The pot life was longer than 1 and less than 2.

D The pot life was equal to or shorter than 1.

Test Example 2: Purification of Aqueous Liquid to be Purified andEvaluation of Performance of Chemical Liquid

[Manufacturing of Chemical Liquid 101 and Chemical Liquid 102]

Sulfuric acid-Hydrogen Peroxide Mixture (SPM) and an aqueous phosphoricacid solution (phosphoric acid content: 85% by mass) were purchased andprepared as a liquid to be purified. SPM is a 4:1 mixed solution (basedon volume) of sulfuric acid and hydrogen peroxide.

Then, chemical liquids 101 and 102 were manufactured using the filteringdevice described in FIG. 20 . In the filtering device shown In FIG. 20 ,a filter BU-1, a tank TU-1, a filter BU-2, a filter F-A, a filter BD-1,a tank TD-1, and a filter BD-2 are connected in series between an inletportion and an outlet portion so as to form a flow path S-20.Furthermore, in the filtering device shown in FIG. 20 , a return flowpath R-20 was formed which is capable of returning a liquid to bepurified to the upstream side of the filter F-A from the downstream side(tank TD-1) of the filter BD-1, and circulation filtration of the liquidto be purified was performed three times.

The following table shows the material components contained in each ofthe filters in the filtering device shown in FIG. 20 and the pore sizeof the filters.

The abbreviations relating to the material components of the filters inthe table will not be described because they are the same as thosedescribed above.

[Manufacturing of Chemical Liquid 103 and Chemical Liquid 104]

A chemical liquid 103 and a chemical liquid 104 were manufactured by thesame method as that used for manufacturing the chemical liquid 101 andthe chemical liquid 102, except that a filtering device (with a filterF-A and a flow path S-25) illustrated in FIG. 25 was used instead of thefiltering device illustrated in FIG. 20 . The material components of thefilter F-A and the like are shown in the table. During the manufacturingof the chemical liquids, circulation filtration was not performed.

[Evaluation 1: Evaluation of Defect Inhibition Performance of ChemicalLiquid (Particle Defects and Stain-Like Defects)]

A bare silicon wafer having a diameter of about 300 mm was prepared, and100 ml of each chemical liquid was jetted at a jetting frequency of 5ml/s for 20 seconds to the wafer that was rotating under the conditionof 500 rpm. Thereafter, the wafer was rotated at 2,000 rpm for 30seconds to perform a spin dry treatment. The resulting wafer was used asa wafer for evaluation. Then, by using a wafer inspection device “SP-5”manufactured by KLA-Tencor Corporation. and a fully automatic defectreview/classification device “SEMVision G6” manufactured by AppliedMaterials, Inc, the number of defects having a size equal to or greaterthan 26 nm existing on the entire surface of the wafer and thecomposition of the defects were investigated.

Among the measured defects, particle-like foreign substances werecounted as particle defects, and others are counted as stain-likedefects. The defect inhibition performance was evaluated based on thefollowing standard. The results are shown in the columns of “particledefect inhibition performance” and “Stain-like defect inhibitionperformance” in the table. “Number of defects” means the total number ofparticle defects and stain-like defects.

A The number of defects was equal to or smaller than 50/wafer.

B The number of defects was greater than 50/wafer and equal to orsmaller than 300/wafer.

C The number of defects was greater than 300/wafer.

[Evaluation 2: Evaluation of Pot Life of Filter]

The liquid to be purified was continuously purified using each of thefiltering devices described in the table. After the liquid to bepurified was passed and the filtering device was stabilized, theobtained chemical liquid was immediately collected for test (initialsample). Then, whenever the amount of the liquid passing through thedevice became 10,000 kg, a chemical liquid obtained after purificationwas collected for test (temporal sample). The chemical liquid collectedfor test was evaluated by the method for evaluating the particle defectinhibition performance of a chemical liquid described in “Evaluation 1”,and the number of defects per unit area was compared with that of theinitial sample. The amount of the chemical liquid passing the devicethat was determined at a point in time when the number of defects in thetemporal sample doubled was adopted as “pot life” of the filter. The potlife obtained in a case (chemical liquid 103) where the filtering devicedescribed in FIG. 25 was used was regarded as 1, and the pot life of thefilter of each device was evaluated based on a ratio to 1. The resultswere evaluated based on the following standard. The evaluation resultsare shown in the table. The evaluation result obtained using the device(chemical liquid 103) in FIG. 25 is described as “Standard”.

A The pot life was equal to or longer than 10.

B The pot life was equal to or longer than 5 and less than 10.

C The pot life was longer than 1 and less than 5.

D The pot life was equal to or shorter than 1.

Test Example 3: Manufacturing of Chemical Liquid as Resist ResinComposition and Evaluation of Performance of Chemical Liquid

[Manufacturing of Chemical Liquid 201]

A resist resin composition 2 containing the following components wasprepared as a liquid to be purified.

Resin A-2 synthesized by the following method: 0.79 g

<Resin (A-2)>

Synthesis of Resin (A-2)

A 2 L flask was filled with 600 g of cyclohexanone and then subjected tonitrogen purging for 1 hour at a flow rate of 100 mL/min. Thereafter,0.02 mol of a polymerization initiator V-601 (manufactured by Wako PureChemical Industries, Ltd.) was added thereto, and the flask was heateduntil the internal temperature became 80° C. Subsequently, the followingmonomers 1 to 3 and 0.02 mol of a polymerization initiator V-601(manufactured by Wako Pure Chemical Industries, Ltd.) were dissolved in200 g of cyclohexanone, thereby preparing a monomer solution. Themonomer solution was added dropwise for 6 hours to the flask heated to80° C. After the dropwise addition ended, the reaction was furtherperformed at 80° C. for 2 hours.

Monomer 1: 0.3 mol

Monomer 2: 0.6 mol

Monomer 3: 0.1 mol

The reaction solution was cooled to room temperature and added dropwiseto 3 L of hexane so as to precipitate a polymer. The filtered solidswere dissolved in 500 mL of acetone, added dropwise again to 3 L ofhexane, and the filtered solids were dried under reduced pressure,thereby obtaining a copolymer (A-2) of the monomers 1 to 3.

A reaction container was filled with 10 g of the polymer obtained asabove, 40 mL of methanol, 200 mL of 1-methoxy-2-propanol, and 1.5 mL ofconcentrated hydrochloric acid, and the mixture was heated to 80° C. andstirred for 5 hours. The reaction solution was left to cool to roomtemperature and added dropwise to 3 L of distilled water. The filteredsolids were dissolved in 200 mL of acetone, added dropwise again to 3 Lof distilled water, and the filtered solids were dried under reducedpressure, thereby obtaining a resin (A-2) (8.5 g). The weight-averagemolecular weight (Mw) of the resin measured by gel permeationchromatography (GPC) (solvent: THF (tetrahydrofuran)) and expressed interms of standard polystyrene was 12,300, and the molecular weightdispersity (Mw/Mn) of the resin was 1.51.

The composition (molar ratio) of the resin was calculated by ¹H-NMR(nuclear magnetic resonance) measurement. The weight-average molecularweight (Mw: in terms of polystyrene) and the dispersity (Mw/Mn) of theresin were calculated by GPC (solvent: THF) spectroscopy.

The composition of the resin A-2 was 30/60/10 (molar ratio) in thisorder from the constitutional unit at the very left. The resin A-2 had aweight-average molecular weight (Mw) of 12,300 and Mw/Mn of 1.51.

The following aid generator (B-2): 0.18 g

The following basic compound (E-1): 0.03 g

Propylene glycol monomethyl ether acetate: 45 g

Propylene glycol monomethyl ether: 30 g

A chemical liquid 201 was manufactured using the filtering deviceillustrated in FIG. 26 . In the filtering device in FIG. 26 , a filterBU-1, a tank TU-1, a filter F-A, and a filter BD-1 are connected inseries between an inlet portion and an outlet portion. The units form aflow path S-26 together with piping. Furthermore, a return flow pathR-26 is formed which is capable of returning a liquid to be purified toa position, which is on the downstream side of the filter BU-1 and onthe upstream side of the tank TU-1, from the downstream side of thefilter BD-1. The liquid to be purified was returned by the return flowpath R-26 and then subjected to circulation filtration three times.

The following table shows the material components contained in thefilters used for purification and the pore sizes of the filters.

[Manufacturing of Chemical Liquid 202 and Chemical Liquid 203]

A chemical liquid 202 and a chemical liquid 203 were manufactured by thesame method as that used for manufacturing the chemical liquid 201,except that the filtering device described in the table was used. Duringthe manufacturing of the chemical liquid 203, circulation filtration wasnot performed.

[Manufacturing of Chemical Liquid 204]

A resist resin composition 3 containing the following components wasprepared as a liquid to be purified.

Resin A-14 synthesized by the following method: 0.785 g

<Resin (A-14)>

Synthesis of resin (A-14)

A resin (A-14) having the following structure was obtained by the samemethod as that used for synthesizing the resin (A-2), except that theused monomer was changed.

The composition of the resin A-14 was 20/40/40 (molar ratio) in thisorder from the constitutional unit at the very left. The resin A-14 hada weight-average molecular weight (Mw) of 11,000 and Mw/Mn of 1.45.

The following acid generator (B-9): 0.18 g

The following basic compound (E-2): 0.03 g

Propylene glycol monomethyl ether acetate: 45 g

Cyclohexanone: 30 g

The following hydrophobic resin (3 b) shown below: 0.005 g

A chemical liquid 204 was manufactured using the filtering deviceillustrated in FIG. 26 . In the filtering device in FIG. 26 , a filterBU-1, a tank TU-1, a filter F-A, and a filter BD-1 are connected inseries between an inlet portion and an outlet portion. The units form aflow path S-26 together with piping. Furthermore, a return flow pathR-26 is formed which is capable of returning a liquid to be purified toa position, which is on the downstream side of the filter BU-1 and onthe upstream side of the tank TU-1, from the downstream side of thefilter BD-1. The liquid to be purified was returned by the return flowpath R-26 and then subjected to circulation filtration three times.

The table shows the material components contained in the filters usedfor purification and the pore sizes of the filters.

[Manufacturing of Chemical Liquid 205 and Chemical Liquid 206]

A chemical liquid 205 and a chemical liquid 206 were manufactured by thesame method as that used for manufacturing the chemical liquid 204,except that the filtering device described in the table was used. Duringthe manufacturing of the chemical liquid 206, circulation filtration wasnot performed.

[Manufacturing of Chemical Liquid 207]

A resist resin composition 4 containing the following components wasprepared as a liquid to be purified.

Resin (A-1)-3 synthesized by the following method: 97% by mass

<Resin (A-1)-3>

The resin (A-1)-3 was synthesized with reference to the description inparagraphs “0131” to “0134” of JP2009-265609A. The repeating units ofthe resin (A-1)-3 are represented by the following formulas, and thecomposition (molar ratio) thereof is 50/40/10 from the left. The resin(A-1)-3 had a weight-average molecular weight of 20,000 and a dispersityrepresented by Mw/Mn of 1.57.

The following acid generator (B-35): 2.5% by mass

C-1 dicyclohexylmethylamine: 0.4% by mass

D-1 fluorine-based surfactant, MEGAFACE F-176 (manufactured by DICCorporation): 0.1% by mass

Here, the content of (A-1)-3 to D-1 means the content in the solidcontents of the resist resin composition 4 based on mass.

Solvent

Propylene glycol monomethyl ether acetate: 80% by mass

Propylene glycol monomethyl ether: 20% by mass

Here, the content of the solvent means the content of each solvent inthe solvents contained in the resist resin composition 4 (contentdetermined by regarding the total mass of the solvents as 100% by mass).The solid contents of the resist resin composition 4 were adjusted to10% by mass.

A chemical liquid 207 was manufactured using the filtering deviceillustrated in FIG. 26 . In the filtering device in FIG. 26 , a filterBU-1, a tank TU-1, a filter F-A, and a filter BD-1 are connected inseries between an inlet portion and an outlet portion. The units form aflow path S-26 together with piping. Furthermore, a return flow pathR-26 is formed which is capable of returning a liquid to be purified toa position, which is on the downstream side of the filter BU-1 and onthe upstream side of the tank TU-1, from the downstream side of thefilter BD-1. The liquid to be purified was returned by the return flowpath R-26 and then subjected to circulation filtration three times.

The table shows the material components contained in the filters usedfor purification and the pore sizes of the filters.

[Manufacturing of Chemical Liquid 208 and Chemical Liquid 209]

A chemical liquid 208 and a chemical liquid 209 were manufactured by thesame method as that used for manufacturing the chemical liquid 207,except that the filtering device described in the table was used. Duringthe manufacturing of the chemical liquid 209, circulation filtration wasnot performed.

[Evaluation of Defect Inhibition Performance of Chemical Liquid: DefectInhibition Performance During EUV Exposure]

By using the chemical liquids 201 to 203, the defect inhibitionperformance (post-development defect inhibition performance and bridgedefect inhibition performance) of the chemical liquids was evaluated bythe following operation. EUV exposure refers to a pattern forming methodby exposure using EUV.

A 12-inch silicon wafer was coated with each of the chemical liquids 201to 203 and baked for 60 seconds under the condition of 120° C., therebyforming a resist film thickness of 40 nm.

(Exposure Conditions for Evaluating Post-Development Defect InhibitionPerformance)

The wafer prepared as above was subjected to EUV exposure using a dipolelighting (Dipole 60x, outer sigma 0.81, inner sigma 0.43) at a lensnumerical aperture (NA) of 0.25. Specifically, the entire surface of thenegative resist was exposed at an exposure amount of 1 mJ/cm² withoutusing a mask.

(Exposure Conditions for Evaluating Bridge Defect InhibitionPerformance)

The wafer prepared as above was subjected to EUV exposure using Quasarlighting (Quasar 45, outer sigma 0.81, inner sigma 0.51) at a lensnumerical aperture (NA) of 0.25. Specifically, through a mask includinga pattern (for evaluating C/H removability) for forming a contact holepattern with dimensions of a pitch of 60 nm and a hole size of 30 nm ona wafer and a line-and-space (LS) pattern with a line width of 22 nm anda pitch of 50 nm, the exposure amount was adjusted, and then the entiresurface of the wafer was subjected to EUV expose at an exposure amountyielding a line width of 22 nm.

(Development Conditions)

Immediately after the exposure was performed under the above conditions,the wafer was baked for 60 seconds under the condition of 100° C.

Thereafter, by using a shower-type developing machine (ADE3000Smanufactured by Actes Kyosan inc.), the developer (23° C.) was sprayedand jetted to the wafer, which was rotating at 50 rpm, for 30 seconds ata flow rate of 200 mL/min so as to perform development, therebyobtaining a sample for evaluation.

(Evaluation 1: Evaluation of Bridge Defect Inhibition Performance)

The resolution of the exposed LS pattern was observed using a scanningelectron microscope (CG4600, manufactured by Hitachi, Ltd.) at 200 kmagnification in visual fields (n=300). The number of bridges occurringin the LS pattern in one visual field observed was evaluated and adoptedas the number of bridge defects in the LS pattern. The smaller thenumber of bridge defects, the better the bridge defect inhibitionperformance of the chemical liquid. The results were evaluated accordingto the following standard. The evaluation results are shown in thetable.

A: The number of defects was equal to or smaller than 10 (number/visualfield).

B: The number of defects was greater than 10 (number/visual field) andequal to or smaller than 30 (number/visual field).

C: The number of defects was greater than 30 (number/visual field) andequal to or smaller than 100 (number/visual field).

D: The number of defects was greater than 100 (number/visual field) andequal to or smaller than 300 (number/visual field).

E: The number of defects was greater than 300 (number/visual field).

(Evaluation 2: Evaluation of Post-Development Defect InhibitionPerformance)

For the obtained sample, by using a wafer inspection device “SP-5”manufactured by KLA-Tencor Corporation, the total number of defectshaving a size equal to or greater than 19 nm existing on the entiresurface of the wafer was measured. The results were evaluated accordingto the following standard. The evaluation results are shown in thetable.

A: The number of defects was equal to or smaller than 200/wafer.

B: The number of defects was greater than 200/wafer and equal to orsmaller than 500/wafer.

C: The number of defects was greater than 500/wafer and equal to orsmaller than 1,000/wafer.

D: The number of defects was greater than 1,000/wafer and equal to orsmaller than 1,500/wafer.

E: The number of defects was greater than 1,500/wafer.

[Evaluation of Defect Inhibition Performance of Chemical Liquid: DefectInhibition Performance During ArF Expose]

By using the chemical liquids 204 to 206, the defect inhibitionperformance (post-development defect inhibition performance and bridgedefect inhibition performance) of the chemical liquids was evaluated bythe following operation. The ArF exposure means a pattern forming methodby exposure using an ArF excimer laser.

A 12-inch silicon wafer was coated with each of the chemical liquids 204to 206 and baked for 60 seconds under the condition of 90° C. to 120°C., thereby forming a resist film thickness of 40 nm.

Before being coated with the resist film, the silicon wafer was coatedwith an organic antireflection film ARC29SR (manufactured by BrewerScience Inc.) and baked for 60 seconds at 205° C. so as to form anantireflection film having a film thickness of 86 nm.

(Exposure Conditions for Evaluating Post-Development Defect InhibitionPerformance)

The wafer prepared as above was subjected to ArF exposure using an ArFexcimer laser immersion scanner (XT1700i manufactured by ASML, NA1.20,Dipole, outer sigma 0.900, inner sigma 0.700, Y polarization).Specifically, the entire surface of the negative resist was exposed atan exposure amount of 1 mJ/cm² without using a mask.

(Exposure Conditions for Evaluating Bridge Defect InhibitionPerformance)

The obtained wafer was subjected to pattern exposure using an ArFexcimer laser immersion scanner (XT1700i manufactured by ASML, NA1.20,Dipole, outer sigma 0.900, inner sigma 0.700, Y polarization). As areticle, a 6% halftone mask having a line size=50 nm and aline:space=1:1 was used. Ultrapure water was used as an immersionsolution.

The conditions were adjusted so as to obtain a line-and-space patternhaving a pitch of 100 nm, a space width of 35 nm, and a line width of 65nm.

(Development Conditions)

The wafer was baked (Post Exposure Bake; PEB) at 100° C. and thensubjected to puddle development in a developer for 30 seconds, therebypreparing a wafer in which a pattern was formed. In a case where arinsing treatment was performed, the wafer was developed by puddling for30 seconds in a developer, then rinsed by puddling in a rinsing solutionbefore being dried, and then rotated for 30 seconds at a rotation speedof 4,000 rpm. In this way, a sample for evaluation was obtained.

(Evaluation 1: Evaluation of Bridge Defect Inhibition Performance)

The resolution of the exposed LS pattern was observed using a scanningelectron microscope (CG4600, manufactured by Hitachi, Ltd.) at 200 kmagnification in visual fields (n=300). The number of bridges occurringin the LS pattern in one visual field observed was evaluated and adoptedas the number of bridge defects in the LS pattern. The smaller thenumber of bridge defects, the better the bridge defect inhibitionperformance of the chemical liquid. The results were evaluated accordingto the following standard. The evaluation results are shown in thetable.

A: The number of defects was equal to or smaller than 10 (number/visualfield).

B: The number of defects was greater than 10 (number/visual field) andequal to or smaller than 30 (number/visual field).

C: The number of defects was greater than 30 (number/visual field) andequal to or smaller than 100 (number/visual field).

D: The number of defects was greater than 100 (number/visual field) andequal to or smaller than 300 (number/visual field).

E: The number of defects was greater than 300 (number/visual field).

(Evaluation 2: Evaluation of Post-Development Defect InhibitionPerformance)

For the obtained sample, by using a wafer inspection device “SP-5”manufactured by KLA-Tencor Corporation, the total number of defectshaving a size equal to or greater than 19 nm existing on the entiresurface of the wafer was measured. The results were evaluated accordingto the following standard. The evaluation results are shown in thetable.

A: The number of defects was equal to or smaller than 200/wafer.

B: The number of defects was greater than 200/wafer and equal to orsmaller than 500/wafer.

C: The number of defects was greater than 500/wafer and equal to orsmaller than 1,000/wafer.

D: The number of defects was greater than 1,000/wafer and equal to orsmaller than 1,500/wafer.

E: The number of defects was greater than 1,500/wafer.

[Evaluation of Defect Inhibition Performance of Chemical Liquid: DefectInhibition Performance During KRF Expose]

By using the chemical liquids 207 to 209, the defect inhibitionperformance (post-development defect inhibition performance and bridgedefect inhibition performance) of the chemical liquids was evaluated bythe following operation. KrF means a pattern forming method by exposureusing a KrF excimer laser.

The silicon wafer was treated with hexamethyldisilazane (HMDS) (110° C.for 35 seconds), and by using the chemical liquids 207 to 209, a resistfilm having a thickness of 100 nm was formed on the wafer. Before thecoating with the chemical liquids, an oxide film having a thickness of100 nm was formed on the silicon wafer.

By using a KrF excimer laser scanner (PAS5500/850 manufactured by ASML)(NA 0.80), KrF expose was performed on the wafer prepared as above.Specifically, the entire surface of the negative resist was exposed atan exposure amount of 1 mJ/cm² without using a mask.

(Exposure Conditions for Evaluating Bridge Defect InhibitionPerformance)

The obtained wafer was subjected to pattern exposure using a KrF excimerlaser scanner (PAS5500/850, manufactured by ASML) (NA 0.80). As areticle, a binary mask was used which had a line-and-space pattern witha line size of 175 nm and a space size of 263 nm. The conditions wereadjusted so as to obtain a line-and-space pattern having a pitch of 438nm, a space width of 130 nm, and a line width of 308 nm.

(Development Conditions)

Then, after baking (Post Exposure Bake; PEB) under the condition of 100°C. for 60 seconds, puddle development with a developer was performed for30 seconds, puddle rinsing with a rinsing solution was performed in acase where a rinsing process was carried out, and then the wafer wasrotated for 30 seconds at a rotation speed of 4000 rpm, therebyobtaining a sample for evaluation.

As the developer, FHD-5 manufactured by Fuji Film Electronics MaterialsCo., Ltd. was used.

(Evaluation 1: Evaluation of Bridge Defect Inhibition Performance)

The resolution of the exposed LS pattern was observed using a scanningelectron microscope (CG4600, manufactured by Hitachi, Ltd.) at 200 kmagnification in visual fields (n=300). The number of bridges occurringin the LS pattern in one visual field observed was evaluated and adoptedas the number of bridge defects in the LS pattern. The smaller thenumber of bridge defects, the better the bridge defect inhibitionperformance of the chemical liquid. The results were evaluated accordingto the following standard. The evaluation results are shown in thetable.

A: The number of defects was equal to or smaller than 10 (number/visualfield).

B: The number of defects was greater than 10 (number/visual field) andequal to or smaller than 30 (number/visual field).

C: The number of defects was greater than 30 (number/visual field) andequal to or smaller than 100 (number/visual field).

D: The number of defects was greater than 100 (number/visual field) andequal to or smaller than 300 (number/visual field).

E: The number of defects was greater than 300 (number/visual field).

(Evaluation 2: Evaluation of Post-Development Defect InhibitionPerformance)

For the obtained sample, by using a wafer inspection device “SP-5”manufactured by KLA-Tencor Corporation, the total number of defectshaving a size equal to or greater than 19 nm existing on the entiresurface of the wafer was measured. The results were evaluated accordingto the following standard. The evaluation results are shown in thetable.

A: The number of defects was equal to or smaller than 200/wafer.

B: The number of defects was greater than 200/wafer and equal to orsmaller than 500/wafer.

C: The number of defects was greater than 500/wafer and equal to orsmaller than 1,000/wafer.

D: The number of defects was greater than 1,000/wafer and equal to orsmaller than 1,500/wafer.

E: The number of defects was greater than 1,500/wafer.

[Evaluation 3: Evaluation of Pot Life of Filter]

The liquid to be purified was continuously purified using each of thefiltering devices described in the table. After the liquid to bepurified was passed and the filtering device was stabilized, theobtained chemical liquid was immediately collected for test (initialsample). Then, whenever the amount of the liquid passing through thedevice became 10,000 kg, a chemical liquid obtained after purificationwas collected for test (temporal sample). The chemical liquid collectedfor test was evaluated by the method for evaluating the bridge defectinhibition performance of a chemical liquid described in “Evaluation 1”,and the number of defects per unit area was compared with that of theinitial sample. The amount of the chemical liquid passing the devicethat was determined at a point in time when the number of defects in thetemporal sample doubled was adopted as “pot life” of the filter. The potlife (chemical liquid 201) obtained in a case where the filtering devicedescribed in FIG. 25 was used was regarded as 1, and the pot life of thefilter of each device was evaluated based on a ratio to 1. The resultswere evaluated based on the following standard. The evaluation resultsare shown in the table. The evaluation result obtained using the device(chemical liquid 201) in FIG. 25 is described as “Standard”.

AA The pot life was equal to or longer than 10.

A The pot life was equal to or longer than 5 and less than 10.

B The pot life was equal to or longer than 2 and less than 5.

C The pot life was longer than 1 and less than 2.

D The pot life was equal to or shorter than 1.

TABLE 1 Liquid to be purified Purification device SP value (filteringdevice) Solvent (MPa)^(1/2) Pre-washing of filter Distiller ChemicalFIG. 14 CHN 20.3 PGMEA 1 day immersion Duplex liquid 1  Chemical FIG. 15CHN 20.3 PGMEA 1 day immersion Duplex liquid 2  Chemical FIG. 16 CHN20.3 PGMEA 1 day immersion Duplex liquid 3  Chemical FIG. 14 CHN 20.3PGMEA 1 day immersion Duplex liquid 4  Chemical FIG. 17 CHN 20.3 PGMEA 1day immersion Duplex liquid 5  Chemical FIG. 14 CHN 20.3 PGMEA 1 dayimmersion Duplex liquid 6  Chemical FIG. 14 CHN 20.3 PGMEA 1 dayimmersion Duplex liquid 7  Chemical FIG. 14 CHN 20.3 PGMEA 1 dayimmersion Duplex liquid 8  Chemical FIG. 14 CHN 20.3 PGMEA 1 dayimmersion Duplex liquid 9  Chemical FIG. 14 CHN 20.3 PGMEA 1 dayimmersion Duplex liquid 10 Chemical FIG. 14 CHN 20.3 PGMEA 1 dayimmersion Duplex liquid 11 Chemical FIG. 18 CHN 20.3 PGMEA 1 dayimmersion Duplex liquid 12 Chemical FIG. 14 CHN 20.3 PGMEA 1 dayimmersion Duplex liquid 13 Chemical FIG. 19 CHN 20.3 PGMEA 1 dayimmersion Duplex liquid 14 Chemical FIG. 14 CHN 20.3 — Duplex liquid 15Chemical FIG. 20 CHN 20.3 PGMEA 1 day immersion — liquid 16 ChemicalFIG. 21 CHN 20.3 PGMEA 1 day immersion — liquid 17 Chemical FIG. 22 CHN20.3 PGMEA 1 day immersion — liquid 18 Chemical FIG. 20 CHN 20.3 PGMEA 1day immersion — liquid 19 Chemical FIG. 10 CHN 20.3 PGMEA 1 dayimmersion — liquid 20 Chemical FIG. 20 CHN 20.3 PGMEA 1 day immersion —liquid 21 Chemical FIG. 20 CHN 20.3 PGMEA 1 day immersion — liquid 22Chemical FIG. 20 CHN 20.3 PGMEA 1 day immersion — liquid 23 ChemicalFIG. 20 CHN 20.3 PGMEA 1 day immersion — liquid 24 Chemical FIG. 20 CHN20.3 PGMEA 1 day immersion — liquid 25 Chemical FIG. 20 CHN 20.3 PGMEA 1day immersion — liquid 26 Chemical FIG. 20 CHN 20.3 PGMEA 1 dayimmersion — liquid 27 Chemical FIG. 20 CHN 20.3 PGMEA 1 day immersion —liquid 28 Chemical FIG. 20 CHN 20.3 PGMEA 1 day immersion — liquid 29Chemical FIG. 20 CHN 20.3 — — liquid 30 Chemical FIG. 14 PGMEA/PGME 19.4PGMEA 1 day immersion Duplex liquid 31 (7:3) Chemical FIG. 14 nBA 17.8PGMEA 1 day immersion Duplex liquid 32 Chemical FIG. 14 PC/PGMEA 18.2PGMEA 1 day immersion Duplex liquid 33 (1:9) Chemical FIG. 24 CHN 20.3PGMEA 1 day immersion Duplex liquid 34 Chemical FIG. 14 MIBC 22.7 PGMEA1 day immersion Duplex liquid 35 Chemical FIG. 14 MIBC 22.7 PGMEA 1 dayimmersion Duplex liquid 36 Chemical FIG. 14 PGME 23.1 PGMEA 1 dayimmersion Duplex liquid 37 Chemical FIG. 14 PGME 23.1 PGMEA 1 dayimmersion Duplex liquid 38 Chemical FIG. 14 PGMEA 17.8 PGMEA 1 dayimmersion Duplex liquid 39 Chemical FIG. 14 PGMEA 17.8 PGMEA 1 dayimmersion Duplex liquid 40 Chemical FIG. 14 PC 21.5 PGMEA 1 dayimmersion Duplex liquid 41 Chemical FIG. 14 PC 21.5 PGMEA 1 dayimmersion Duplex liquid 42 Chemical FIG. 14 CHN 20.3 PGMEA 1 dayimmersion Duplex liquid 43 Chemical FIG. 14 CHN 20.3 PGMEA 1 dayimmersion Duplex liquid 44 Chemical FIG. 14 nBA 17.8 PGMEA 1 dayimmersion Duplex liquid 45 Chemical FIG. 14 nBA 17.8 PGMEA 1 dayimmersion Duplex liquid 46 Chemical FIG. 14 iAA 17.4 PGMEA 1 dayimmersion Duplex liquid 47 Chemical FIG. 14 iAA 17.4 PGMEA 1 dayimmersion Duplex liquid 48 Chemical FIG. 14 EL 21.7 PGMEA 1 dayimmersion Duplex liquid 49 Chemical FIG. 14 EL 21.7 PGMEA 1 dayimmersion Duplex liquid 50 Chemical FIG. 14 PGME 23.1 PGMEA 1 dayimmersion Duplex liquid 51 Chemical FIG. 16 PGME 23.1 PGMEA 1 dayimmersion Duplex liquid 52 Chemical FIG. 14 PGMEA 17.8 PGMEA 1 dayimmersion Duplex liquid 53 Chemical FIG. 16 PGMEA 17.8 PGMEA 1 dayimmersion Duplex liquid 54 Chemical FIG. 14 CHN 20.3 PGMEA 1 dayimmersion Duplex liquid 55 Chemical FIG. 16 CHN 20.3 PGMEA 1 dayimmersion Duplex liquid 56 Chemical FIG. 19 CHN 20.3 PGMEA 1 dayimmersion Duplex liquid 57 Chemical FIG. 19 PGMEA 17.8 PGMEA 1 dayimmersion Duplex liquid 58 Chemical FIG. 19 nBA 17.8 PGMEA 1 dayimmersion Duplex liquid 59 Chemical FIG. 19 MIBC 22.7 PGMEA 1 dayimmersion Duplex liquid 60 Chemical FIG. 19 CHN 20.3 PGMEA 1 dayimmersion — liquid 61 Chemical FIG. 19 PGMEA 17.8 PGMEA 1 day immersion— liquid 62 Chemical FIG. 19 nBA 17.8 PGMEA 1 day immersion — liquid 63Chemical FIG. 19 MIBC 22.7 PGMEA 1 day immersion — liquid 64 ChemicalFIG. 14 PGMEA/PGME 19.4 PGMEA 1 day immersion Duplex liquid 65 (7:3)Chemical FIG. 14 nBA 17.8 PGMEA 1 day immersion Duplex liquid 66Chemical FIG. 31 PGMEA/PGME 19.4 PGMEA 1 day immersion Duplex liquid 67(7:3) Chemical FIG. 31 nBA 17.8 PGMEA 1 day immersion Duplex liquid 68BU-1 BU-2 BU-3 Material Pore size Material Pore size Material Pore sizecomponent (nm) component (nm) component (nm) Chemical liquid 1  UPE  50IEX 15 — — Chemical liquid 2  IEX  15 — — — — Chemical liquid 3  PP 200IEX 15 Nylon 20 Chemical liquid 4  PP 200 IEX 200  — — Chemical liquid5  PP 200 IEX 15 — — Chemical liquid 6  PTFE  20 IEX 15 — — Chemicalliquid 7  PP 200 IEX 15 — — Chemical liquid 8  PP 200 IEX 15 — —Chemical liquid 9  PP 200 IEX 15 — — Chemical liquid 10 PP 200 IEX 15 —— Chemical liquid 11 PP 200 IEX 15 — — Chemical liquid 12 PP 200 — — — —Chemical liquid 13 PP 200 IEX 15 — — Chemical liquid 14 PP 200 IEX 15 —— Chemical liquid 15 PP 200 IEX 15 — — Chemical liquid 16 PP 200 IEX 15— — Chemical liquid 17 IEX  15 — — — — Chemical liquid 18 PP 200 IEX 15Nylon 20 Chemical liquid 19 PP 200 IEX 200  — — Chemical liquid 20 PP200 IEX 15 — — Chemical liquid 21 PTFE  20 IEX 15 — — Chemical liquid 22PP 200 IEX 15 — — Chemical liquid 23 PP 200 IEX 15 — — Chemical liquid24 PP 200 IEX 15 — — Chemical liquid 25 PP 200 IEX 15 — — Chemicalliquid 26 PP 200 IEX 15 — — Chemical liquid 27 PP 200 — — — — Chemicalliquid 28 PP 200 IEX 15 — — Chemical liquid 29 PP 200 IEX 15 — —Chemical liquid 30 PP 200 IEX 15 — — Chemical liquid 31 PP 200 IEX 15 —— Chemical liquid 32 PP 200 IEX 15 — — Chemical liquid 33 PP 200 IEX 15— — Chemical liquid 34 — — — — — — Chemical liquid 35 PP 200 IEX 15 — —Chemical liquid 36 PP 200 IEX 15 — — Chemical liquid 37 PP 200 IEX 15 —— Chemical liquid 38 PP 200 IEX 15 — — Chemical liquid 39 PP 200 IEX 15— — Chemical liquid 40 PP 200 IEX 15 — — Chemical liquid 41 PP 200 IEX15 — — Chemical liquid 42 PP 200 IEX 15 — — Chemical liquid 43 PP 200IEX 15 — — Chemical liquid 44 PP 200 IEX 15 — — Chemical liquid 45 PP200 IEX 15 — — Chemical liquid 46 PP 200 IEX 15 — — Chemical liquid 47PP 200 IEX 15 — — Chemical liquid 48 PP 200 IEX 15 — — Chemical liquid49 PP 200 IEX 15 — — Chemical liquid 50 PP 200 IEX 15 — — Chemicalliquid 51 PP 200 IEX 15 — — Chemical liquid 52 PP 200 IEX 15 Nylon 10Chemical liquid 53 PP 200 IEX 15 — — Chemical liquid 54 PP 200 IEX 15Nylon 10 Chemical liquid 55 PP 200 IEX 15 — — Chemical liquid 56 PP 200IEX 15 Nylon 10 Chemical liquid 57 PP 200 IEX 15 Nylon 10 Chemicalliquid 58 PP 200 IEX 15 Nylon 10 Chemical liquid 59 PP 200 IEX 15 Nylon10 Chemical liquid 60 PP 200 IEX 15 Nylon 10 Chemical liquid 61 PP 200IEX 15 Nylon 10 Chemical liquid 62 PP 200 IEX 15 Nylon 10 Chemicalliquid 63 PP 200 IEX 15 Nylon 10 Chemical liquid 64 PP 200 IEX 15 Nylon10 Chemical liquid 65 PP 200 HDPE 50 — — Chemical liquid 66 PP 200 HDPE50 — — Chemical liquid 67 — — — — — — Chemical liquid 68 — — — — — —BU-4 F-A BD-1 Material Pore size Tank Material Pore size Material Poresize component (nm) TU-1 TU-2 component (nm) component (nm) Chemical — —Present — PTFE-1 10 Nylon 10 liquid 1  Chemical — — Present — PTFE-1 10Nylon 10 liquid 2  Chemical Nylon 20 Present Present PTFE-1  7 — —liquid 3  Chemical — — Present — PTFE-1 10 Nylon 10 liquid 4  Chemical —— — — PTFE-1 10 Nylon 10 liquid 5  Chemical — — Present — PTFE-2 12Nylon 10 liquid 6  Chemical — — Present — PTFE-3 20 Nylon 10 liquid 7 Chemical — — Present — PTFE-4 15 Nylon 10 liquid 8  Chemical — — Present— PTFE-5  7 Nylon 10 liquid 9  Chemical — — Present — PTFE-6 10 Nylon 10liquid 10 Chemical — — Present — PTFE-7 10 Nylon 10 liquid 11 Chemical —— Present — PTFE-8 12 Nylon 10 liquid 12 Chemical — — Present — PTFE-915 PTFE 10 liquid 13 Chemical — — Present — PTFE-2  7 Nylon 10 liquid 14Chemical — — Present — PTFE-3  7 Nylon 10 liquid 15 Chemical — — Present— PTFE-5 10 Nylon 10 liquid 16 Chemical — — Present — PTFE-8 15 Nylon 10liquid 17 Chemical Nylon 20 Present Present PTFE-3  7 — — liquid 18Chemical — — Present — PTFE-1 10 Nylon 10 liquid 19 Chemical — — — —PTFE-2 12 Nylon 10 liquid 20 Chemical — — Present — PTFE-3 15 Nylon 10liquid 21 Chemical — — Present — PTFE-4  7 Nylon 10 liquid 22 Chemical —— Present — PTFE-1  7 Nylon 10 liquid 23 Chemical — — Present — PTFE-210 Nylon 10 liquid 24 Chemical — — Present — PTFE-1 10 Nylon 10 liquid25 Chemical — — Present — PTFE-2 12 Nylon 10 liquid 26 Chemical — —Present — PTFE-3 15 Nylon 10 liquid 27 Chemical — — Present — PTFE-4  7PTFE 10 liquid 28 Chemical — — Present — PTFE-3  7 Nylon 10 liquid 29Chemical — — Present — PTFE-4 10 Nylon 10 liquid 30 Chemical — — Present— PTFE-1 10 Nylon 10 liquid 31 Chemical — — Present — PTFE-2 12 Nylon 10liquid 32 Chemical — — Present — PTFE-3 15 Nylon 10 liquid 33 Chemical —— — — PTFE-4  7 — — liquid 34 Chemical — — Present — PTFE-3 12 Nylon 10liquid 35 Chemical — — Present — PTFE-3 15 Nylon 10 liquid 36 Chemical —— Present — PTFE-2 12 Nylon 10 liquid 37 Chemical — — Present — PTFE-215 Nylon 10 liquid 38 Chemical — — Present — PTFE-1 12 Nylon 10 liquid39 Chemical — — Present — PTFE-1 15 Nylon 10 liquid 40 Chemical — —Present — PTFE-5 12 Nylon 10 liquid 41 Chemical — — Present — PTFE-5 15Nylon 10 liquid 42 Chemical — — Present — PTFE-6 12 Nylon 10 liquid 43Chemical — — Present — PTFE-6 15 Nylon 10 liquid 44 Chemical — — Present— PTFE-2 12 Nylon 10 liquid 45 Chemical — — Present — PTFE-2 15 Nylon 10liquid 46 Chemical — — Present — PTFE-1 12 Nylon 10 liquid 47 Chemical —— Present — PTFE-1 15 Nylon 10 liquid 48 Chemical — — Present — PTFE-312 Nylon 10 liquid 49 Chemical — — Present — PTFE-3 15 Nylon 10 liquid50 Chemical — — Present — PTFE-2 10 UPE 10 liquid 51 Chemical UPE 10Present Present PTFE-2 10 — — liquid 52 Chemical — — Present — PTFE-2 10UPE 10 liquid 53 Chemical UPE 10 Present Present PTFE-2 10 — — liquid 54Chemical — — Present — PTFE-2 10 UPE 10 liquid 55 Chemical UPE 10Present Present PTFE-2 10 — — liquid 56 Chemical UPE 10 Present — PTFE-2 7 Nylon  5 liquid 57 Chemical UPE 10 Present — PTFE-1  7 Nylon  5liquid 58 Chemical UPE 10 Present — PTFE-1  7 Nylon  5 liquid 59Chemical UPE 10 Present — PTFE-3  7 Nylon  5 liquid 60 Chemical UPE 10Present — PTFE-2  7 Nylon  5 liquid 61 Chemical UPE 10 Present — PTFE-1 7 Nylon  5 liquid 62 Chemical UPE 10 Present — PTFE-1  7 Nylon  5liquid 63 Chemical UPE 10 Present — PTFE-3  7 Nylon  5 liquid 64Chemical — — Present — PTFE-1 10 Nylon 10 liquid 65 Chemical — — Present— PTFE-2 12 Nylon 10 liquid 66 Chemical — — Present — PTFE-1 10 Nylon 10liquid 67 Chemical — — Present — PTFE-2 12 Nylon 10 liquid 68 BD-2 TankMaterial component Pore size (nm) TD-1 Circulation Evaluation methodChemical UPE 3 Present Performed Pre-wetting liquid 1  Chemical UPE 3Present Performed Pre-wetting liquid 2  Chemical — — — PerformedPre-wetting liquid 3  Chemical UPE 3 Present Performed Pre-wettingliquid 4  Chemical UPE 3 Present Performed Pre-wetting liquid 5 Chemical UPE 3 Present Performed Pre-wetting liquid 6  Chemical PTFE 20 Present Performed Pre-wetting liquid 7  Chemical PTFE 7 PresentPerformed Pre-wetting liquid 8  Chemical Nylon 5 Present PerformedPre-wetting liquid 9  Chemical UPE 5 Present Performed Pre-wettingliquid 10 Chemical UPE 1 Present Performed Pre-wetting liquid 11Chemical UPE 3 Present Performed Pre-wetting liquid 12 Chemical UPE 3Present Performed Pre-wetting liquid 13 Chemical UPE 3 — — Pre-wettingliquid 14 Chemical UPE 3 Present Performed Pre-wetting liquid 15Chemical UPE 3 Present Performed Pre-wetting liquid 16 Chemical UPE 3Present Performed Pre-wetting liquid 17 Chemical — — — PerformedPre-wetting liquid 18 Chemical UPE 3 Present Performed Pre-wettingliquid 19 Chemical UPE 3 Present Performed Pre-wetting liquid 20Chemical UPE 3 Present Performed Pre-wetting liquid 21 Chemical PTFE 20 Present Performed Pre-wetting liquid 22 Chemical PTFE 7 PresentPerformed Pre-wetting liquid 23 Chemical Nylon 5 Present PerformedPre-wetting liquid 24 Chemical liquid UPE 3 Present PerformedPre-wetting 25 Chemical liquid UPE 1 Present Performed Pre-wetting 26Chemical liquid UPE 3 Present Performed Pre-wetting 27 Chemical liquidUPE 3 Present Performed Pre-wetting 28 Chemical liquid UPE 3 — —Pre-wetting 29 Chemical liquid UPE 3 Present Performed Pre-wetting 30Chemical liquid UPE 3 Present Performed Pre-wetting 31 Chemical liquidUPE 3 Present Performed Developer 32 Chemical liquid UPE 3 PresentPerformed Pre-wetting 33 Chemical liquid — — — — Pre-wetting 34 Chemicalliquid UPE 5 Present Performed Rinsing 35 Chemical liquid PTFE-5 10 Present Performed Rinsing 36 Chemical liquid UPE 5 Present PerformedPre-wetting 37 Chemical liquid PTFE-8 10  Present Performed Pre-wetting38 Chemical liquid UPE 5 Present Performed Pre-wetting 39 Chemicalliquid PTFE-6 10  Present Performed Pre-wetting 40 Chemical liquid UPE 5Present Performed Pre-wetting 41 Chemical liquid PTFE-4 12  PresentPerformed Pre-wetting 42 Chemical liquid UPE 5 Present PerformedPre-wetting 43 Chemical liquid PTFE-4 12  Present Performed Pre-wetting44 Chemical liquid UPE 5 Present Performed Developer 45 Chemical liquidPTFE-1 7 Present Performed Developer 46 Chemical liquid UPE 5 PresentPerformed Developer 47 Chemical liquid PTFE-2 7 Present PerformedDeveloper 48 Chemical liquid UPE 7 Present Performed Pre-wetting 49Chemical liquid PTFE-4 12  Present Performed Pre-wetting 50 Chemicalliquid Nylon 7 Present Performed Pre-wetting 51 Chemical liquid — — —Performed Pre-wetting 52 Chemical liquid Nylon 7 Present PerformedPre-wetting 53 Chemical liquid — — — Performed Pre-wetting 54 Chemicalliquid Nylon 7 Present Performed Pre-wetting 55 Chemical liquid — — —Performed Pre-wetting 56 Chemical liquid UPE 3 — — Pre-wetting 57Chemical liquid UPE 3 — — Pre-wetting 58 Chemical liquid UPE 3 — —Developer 59 Chemical liquid UPE 3 — — Rinsing 60 Chemical liquid UPE 3— — Pre-wetting 61 Chemical liquid UPE 3 — — Pre-wetting 62 Chemicalliquid UPE 3 — — Developer 63 Chemical liquid UPE 3 — — Rinsing 64Chemical liquid UPE 3 Present Performed Pre-wetting 65 Chemical liquidUPE 3 Present Performed Developer 66 Chemical liquid UPE 3 PresentPerformed Pre-wetting 67 Chemical liquid UPE 3 Present PerformedDeveloper 68 Evaluation 1 Evaluation 2 Residue defect Stain-like defectBridge defect Evaluation 3 inhibition inhibition inhibition Patternwidth Evaluation 4 performance performance performance uniformity Potlife Chemical AA AA AA AA AA liquid 1  Chemical A AA A AA B liquid 2 Chemical AA AA A A AA liquid 3  Chemical A AA B AA AA liquid 4  ChemicalA AA A A AA liquid 5  Chemical A AA AA AA A liquid 6  Chemical A AA A BAA liquid 7  Chemical A AA A A AA liquid 8  Chemical A AA A AA AA liquid9  Chemical A AA AA AA AA liquid 10 Chemical AA AA AA AA AA liquid 11Chemical A AA C A AA liquid 12 Chemical B AA A A AA liquid 13 Chemical BAA A B AA liquid 14 Chemical A B A AA AA liquid 15 Chemical AA B AA AAAA liquid 16 Chemical A B A AA B liquid 17 Chemical AA B A A AA liquid18 Chemical A B B AA AA liquid 19 Chemical A B A A AA liquid 20 ChemicalA B AA AA A liquid 21 Chemical A B A B AA liquid 22 Chemical A B A A AAliquid 23 Chemical A B A AA AA liquid 24 Chemical A B AA AA AA liquid 25Chemical AA B AA AA AA liquid 26 Chemical A B C A AA liquid 27 ChemicalB B A A AA liquid 28 Chemical B B A B AA liquid 29 Chemical A D A AA AAliquid 30 Chemical AA AA AA AA AA liquid 31 Chemical AA AA AA AA AAliquid 32 Chemical AA AA AA AA AA liquid 33 Chemical E E E E Standardliquid 34 Chemical A AA A AA AA liquid 35 Chemical A AA A AA AA liquid36 Chemical A AA A AA AA liquid 37 Chemical A AA A AA AA liquid 38Chemical A A A AA AA liquid 39 Chemical AA AA AA AA AA liquid 40Chemical A AA A AA AA liquid 41 Chemical A AA A AA AA liquid 42 ChemicalA AA A AA AA liquid 43 Chemical A AA A AA AA liquid 44 Chemical A A A AAAA liquid 45 Chemical AA AA AA AA AA liquid 46 Chemical A A A AA AAliquid 47 Chemical AA AA AA AA AA liquid 48 Chemical A AA A AA AA liquid49 Chemical A AA A AA AA liquid 50 Chemical A AA A A AA liquid 51Chemical A AA A A AA liquid 52 Chemical A A A AA AA liquid 53 ChemicalAA AA AA AA AA liquid 54 Chemical A AA A AA AA liquid 55 Chemical A AA AAA AA liquid 56 Chemical AA AA AA AA AA liquid 57 Chemical AA AA AA AAAA liquid 58 Chemical AA AA AA AA AA liquid 59 Chemical AA AA AA AA AAliquid 60 Chemical AA B AA AA AA liquid 61 Chemical AA B AA AA AA liquid62 Chemical AA B AA AA AA liquid 63 Chemical AA B AA AA AA liquid 64Chemical AA AA AA A AA liquid 65 Chemical AA AA AA A AA liquid 66Chemical AA AA A A B liquid 67 Chemical AA AA A A B liquid 68

Table 1 is divided into a first group: Table 1(1-1) to Table 1 (1-5),asecond group: Table 1(2-1) to Table 1(2-5), and athird group: Table1(3-1) to Table 1(3-5).

In the corresponding lines of five tables of each group subdivided fromTable 1, the filters included in the filtering device (or thepurification device) used for the purifying each chemical liquid and theevaluation results of the obtained chemical liquid are described.

For example, in the first line in Table 1(1-1) to Table 1(1-5) as thefirst group, the chemical liquid 1 is described.

The first line shows that the chemical liquid 1 was manufactured by thepurification device described in FIG. 14 , the liquid to be purifiedused for manufacturing the chemical liquid 1 contained CHN(cyclohexanone), and the SP value thereof was 20.3. In addition, thefirst line shows that the filter of the purification device used formanufacturing the chemical liquid 1 was washed in advance under thecondition of “PGMEA 1 day immersion”. Furthermore, the first line showsthat the purification device has a duplex distiller, BU-1(UPE-containing filter having a pore size of 50 nm disposed on theuppermost stream side of the flow path), BU-2 (IEX filter having a poresize of 15 nm disposed on the downstream side of BU-1), a tank TU-1disposed on the upstream side of the filter A (F-A), an a PTFE-1 filterhaving a pore size of 10 nm as F-A (filter A), BD-1 (nylon-containingfilter having a pore size of 10 nm) and BD-2 (UPE-containing filterhaving a pore size of 3 nm) arranged on the downstream side of thefilter F-A, and a tank TD-1 disposed on the downstream side of thefilter F-A. The first line also shows that the circulation filtrationwas “performed”.

The first line also shows that the chemical liquid 1 was evaluated bythe “Pre-wetting” method, the residue defect inhibition performance wasAA, the stain-like defect inhibition performance was AA, the bridgedefect inhibition performance was AA, the pattern width uniformity wasAA, and the pot life of the filter of the purification device was AA.

Similarly, for the chemical liquids 25 to 48, the results are describedin each table of the second group. Furthermore, for the chemical liquids49 to 68, the results are described in each table of the third group.

As is evident from the results shown in the table, the chemical liquids1 to 33 and the chemical liquids 35 to 68, which were purified using thefiltering device (or purification device) having the filter A and thefilter B different from the filter A, had excellent defect inhibitionperformance. In contrast, the chemical liquid 34 purified using thefiltering device without the filter B did not have the desired effect ofthe present invention.

In a case where the SP value of the liquid to be purified was equal toor smaller than 20, the chemical liquid 31 and the chemical liquid 32manufactured by the filtering device (purification device) having thefilter BU had better defect inhibition performance, compared to thechemical liquids 67 and 68 manufactured by the filtering device(purification device) without the filter BU. In other words, it has beenfound that the filtering device having the filter BU is more preferablyused for purifying a liquid to be purified having an SP value equal toor smaller than 20.

In addition, it has been found that in a case where the SP value of theliquid to be purified is equal to or smaller than 20, the filteringdevice has the filter BU, and the filter BU contains a resin having anion exchange group as a material component, the chemical liquid 31 andthe chemical liquid 32 manufactured by the filtering device(purification device) had better defect inhibition performance, comparedto the chemical liquid 65 and the chemical liquid 66 manufactured by thefiltering device (purification device) having the filter BU that hasHDPE as a material component (resin without an ion exchange group). Inother words, it has been found that the filtering device having thefilter BU, which contains a resin having an ion exchange group as amaterial component, is more preferably used for purifying a liquid to bepurified having an SP value equal to or smaller than 20.

TABLE 2 (1-1) BU-1 filtering Liquid to be Material device purifiedPre-washing of filter Distiller component Pore size (nm) Chemical FIG.20 SPM (4:1) PGMEA 1 day immersion — PTFE 200 liquid 101 Chemical FIG.20 85% phosphoric PGMEA 1 day immersion — PTFE 200 liquid 102 acidChemical FIG. 25 SPM (4:1) PGMEA 1 day immersion — — — liquid 103Chemical FIG. 25 85% phosphoric PGMEA 1 day immersion — — — liquid 104acid (1-2) BU-2 F-A BD-1 Material Tank Material Pore size Materialcomponent Pore size (nm) TU-1 component (nm) component Pore size (nm)Chemical PTFE 20 Present PTFE-3 15 PTFE 10 liquid 101 Chemical PTFE 20Present PTFE-4 7 PTFE 10 liquid 102 Chemical — — — PTFE-3 15 — — liquid103 Chemical — — — PTFE-4 7 — — liquid 104 (1-3) Evaluation 1 BD-2Particle defect Stain-like defect Material Pore size Tank inhibitioninhibition Evaluation 2 component (nm) TD-1 Circulation performanceperformance Pot life Chemical PTFE 10 Present Performed A A A liquid 101Chemical PTFE 10 Present Performed A A A liquid 102 Chemical — — — — C BStandard liquid 103 Chemical — — — — C B D liquid 104

Table 2 is divided into Table 2 (1-1) to Table 2 (1-3). In thecorresponding lines of the tables subdivided from Table 2, the filteringdevices used for purifying the chemical liquids and the obtainedevaluation results of chemical liquids are described.

For example, in the first line of each of the subdivision tables, thechemical liquid 101 is described.

The first line shows that the chemical liquid 101 was manufactured bythe filtering device illustrated in FIG. 20 , and the liquid to bepurified used for manufacturing the chemical liquid 101 was SPM (4:1).In addition, the first line shows that the filter of the filteringdevice used for manufacturing the chemical liquid 101 was washed inadvance under the condition of “PGMEA 1 day immersion”. Furthermore, thefirst line shows that the filtering device has BU-1 (a PTFE-containingfilter having a pore size of 200 nm), BU-2 (a PTFE-containing filterhaving a pore size of 20 nm), a tank TU-1 disposed on the upstream sideof the filter F-A, a PTFE-3 filter having a pore size of 15 nm as F-A(filter A), and has BD-1 (a PTFE-containing filter having a pore size of10 nm), BD-2 (a PTFE-containing filter having a pore size of 10 nm), anda tank TD-1 which are disposed on the downstream side of the filter F-A.The first line also shows that the circulation filtration was“performed”.

As is evident from the first line, the chemical liquid 101 was evaluatedas A for the particle defect inhibition performance, A for thestain-like defect inhibition performance, and

A for the pot life of the filter of the filtering device. Likewise, forthe chemical liquids 102 to 104, the results are described in the abovetables.

As is evident from the results shown in the table, the chemical liquid101 and the chemical liquid 102, which were purified using the filteringdevice (or purification device) having the filter A and the filter Bdifferent from the filter A, had excellent defect inhibitionperformance. In contrast, the chemical liquid 103 and the chemicalliquid 104 purified using the filtering device without the filter B didnot have the desired effect of the present invention. From the aboveresults, it has been found that the filtering device according to anembodiment of the present invention is also extremely effective forpurifying an aqueous liquid to be purified.

TABLE 3 (1-1) filtering device Liquid to be purified Pre-washing offilter Distiller Chemical FIG. 26 Resist resin composition 2 PEMEA 1 dayimmersion Absent liquid 201 Chemical FIG. 27 Resist resin composition 2PEMEA 1 day immersion Absent liquid 202 Chemical FIG. 25 Resist resincomposition 2 PEMEA 1 day immersion Absent liquid 203 Chemical FIG. 26Resist resin composition 3 PEMEA 1 day immersion Absent liquid 204Chemical FIG. 27 Resist resin composition 3 PEMEA 1 day immersion Absentliquid 205 Chemical FIG. 25 Resist resin composition 3 PEMEA 1 dayimmersion Absent liquid 206 Chemical FIG. 26 Resist resin composition 4PEMEA 1 day immersion Absent liquid 207 Chemical FIG. 27 Resist resincomposition 4 PEMEA 1 day immersion Absent liquid 208 Chemical FIG. 25Resist resin composition 4 PEMEA 1 day immersion Absent liquid 209 (1-2)BU-1 BU-2 F-A Material Pore size Material Pore size Tank Material Poresize component (nm) component (nm) TU-1 component (nm) Chemical liquidNylon 10 — — Present PTFE-3 15 201 Chemical liquid Nylon 20 Nylon 10Present PTFE-3 15 202 Chemical liquid — — — — — PTFE-3 15 203 Chemicalliquid Nylon 10 — — Present PTFE-4 7 204 Chemical liquid Nylon 20 Nylon10 Present PTFE-4 7 205 Chemical liquid — — — — — PTFE-4 7 206 Chemicalliquid Nylon 10 — — Present PTFE-1 10 207 Chemical liquid Nylon 20 Nylon10 Present PTFE-1 10 208 Chemical liquid — — — — — PTFE-1 10 209 (1-3)BD-1 Evaluation 1 Evaluation 2 Pore Bridge defect Post-developmentEvaluation Material size Tank inhibition defect inhibition 3 component(nm) TD-1 Circulation performance performance Pot life Chemical UPE 1 —Performed A A A liquid 201 Chemical UPE 1 — Performed A A AA liquid 202Chemical — — — — C C Standard liquid 203 Chemical UPE 1 — Performed A AA liquid 204 Chemical UPE 1 — Performed A A AA liquid 205 Chemical — — —— C C D liquid 206 Chemical UPE 1 — Performed A A A liquid 207 ChemicalUPE 1 — Performed A A AA liquid 208 Chemical — — — — C C D liquid 209

Table is divided into Table (1-1) to Table (1-3). In the correspondinglines of the tables subdivided from Table 3, the filtering devices usedfor purifying the chemical liquids and the obtained evaluation resultsof chemical liquids are described.

For example, in the first line of each of the subdivision tables, thechemical liquid 201 is described.

The first line shows that the chemical liquid 201 was manufactured bythe filtering device illustrated in FIG. 26 , and the liquid to bepurified used for manufacturing the chemical liquid 201 was the resistresin composition 2. In addition, the first line shows that the filterof the filtering device used for manufacturing the chemical liquid 201was washed in advance under the condition of “PGMEA1 day immersion”.Furthermore, the first line shows that the filtering device has BU-1 (anylon-containing filter having a pore size of 10 nm), a tank TU-1 on theupstream side of the filter F-A, a PTFE-3 filter having a pore size of10 nm as F-A (filter A), and BD-1 (a UPE-containing filter having a poresize of 1 nm) on the downstream side of the filter F-A. The first linealso shows that the circulation filtration was “performed”.

As is evident from the first line, the chemical liquid 201 was evaluatedas A for the bridge defect inhibition performance, A for thepost-development defect inhibition performance, and A for the pot lifeof the filter of the filtering device.

Likewise, for the chemical liquids 202 to 209, the results are describedin the above tables.

As is evident from the results shown in the table, the chemical liquids201, 202, 204, 205, 207, and 208, which were purified using thefiltering device (or purification device) having the filter A and thefilter B different from the filter A, had excellent defect inhibitionperformance. In contrast, the chemical liquid 203, the chemical liquid206, and the chemical liquid 209 purified using the filtering devicewithout the filter B did not have the desired effect of the presentinvention. From the above results, it has been found that the filteringdevice according to an embodiment of the present invention also bringsabout excellent effects even in a case where a resist resin compositionis used as a liquid to be purified.

For the chemical liquids 1 to 13, the chemical liquids 15 to 28, thechemical liquids 30 to 33, the chemical liquids 35 to 56, the chemicalliquids 65 to 68, the chemical liquids 101 and 102, the chemical liquids201 and 202, the chemical liquids 204 and 205, and the chemical liquids207 and 208, chemical liquids were prepared using the same filteringdevice (purification device) as that described in the tables. In thiscase, circulation filtration was not performed. The obtained chemicalliquids were evaluated in terms of the items described in the tables. Asa result, the obtained chemical liquids were found to have excellentdefect inhibition performance. Furthermore, it has been confirmed thatthe pot life of the filter is also excellent as described above.

Generally, from the viewpoint of production cost, it is preferable toperform purification without circulation filtration. In contrast,because the filter A included in the filtering device according to anembodiment of the present invention uses a porous base material made ofpolyfluorocarbon as a base material, the amount of impurities that arecaused by the circulation filtration and unintentionally mixed into theliquid to be purified from the filter A is further reduced. In thisrespect, as the filter A, a porous base material made of PTFE is morepreferable.

EXPLANATION OF REFERENCES

-   -   100, 200, 300, 400, 500, 600, 700, 800, 900, 1000: filtering        device    -   101: inlet portion    -   102: outlet portion    -   103, 104, 201, 601, 104-1, 104-2: filter    -   105, 202, 301, 302, 402, 501, 502, 602, 701, 801, 802, 803, 804,        901, 1001, 1002, 1003, 1104, 1105, 1305: piping    -   401, 401(a), 401(b): tank    -   1100: manufacturing plant    -   1101: distillation device    -   1102, 1203, 1303, 1304: distiller    -   1103: portable tank    -   1106: transporting unit    -   1200, 1300: purification device    -   1201, 1301: second inlet portion    -   1202, 1302: second outlet portion

What is claimed is:
 1. A filtering device for obtaining a chemicalliquid by purifying a liquid to be purified, the filtering devicecomprising: an inlet portion; an outlet portion; a filter A; at leastone filter B different from the filter A; and a flow path which includesthe filter A and the filter B arranged in series and extends from theinlet portion to the outlet portion, wherein the filter A has a porousbase material made of polyfluorocarbon and a coating layer which isdisposed to cover the porous base material and contains a resin havingan adsorptive group, and the coating layer is formed on an inner surfaceof a pore of the porous base material.
 2. The filtering device accordingto claim 1, wherein the adsorptive group is a group having at least onekind of group selected from the group consisting of an ether group, ahydroxyl group, a thioether group, a thiol group, a quaternary ammoniumgroup, a carboxylic acid group, and a sulfonic acid group.
 3. Thefiltering device according to claim 1, wherein the filter B includes atleast one filter BU disposed on an upstream side of the filter A on theflow path.
 4. The filtering device according to claim 3, wherein the atleast one filter BU has a pore size larger than a pore size of thefilter A.
 5. The filtering device according to claim 3, wherein the atleast one filter BU has a pore size equal to or greater than 20 nm. 6.The filtering device according to claim 3, wherein the at least onefilter BU contains a resin having an ion exchange group.
 7. Thefiltering device according to claim 6, wherein the ion exchange group isat least one kind of ion exchange group selected from the groupconsisting of an acid group, a base group, an amide group, and an imidegroup.
 8. The filtering device according to claim 3, wherein the atleast one filter BU is different from the filter A in terms of material.9. The filtering device according to claim 3, further comprising: areturn flow path capable of returning the liquid to be purified to anupstream side of a first reference filter from a downstream side of thefirst reference filter, wherein the first reference filter consists ofat least one kind of filter selected from the group consisting of thefilter A and the filter BU.
 10. The filtering device according to claim1, wherein the filter B includes at least a filter BD disposed on adownstream side of the filter A on the flow path.
 11. The filteringdevice according to claim 10, wherein the at least one filter BD has apore size smaller than a pore size of the filter A.
 12. The filteringdevice according to claim 10, wherein the at least one filter BD has apore size equal to or smaller than 20 nm.
 13. The filtering deviceaccording to claim 10, wherein the filter BD contains at least one kindof compound selected from the group consisting of polyolefin, polyamide,polyfluorocarbon, polystyrene, polysulfone, and polyethersulfone. 14.The filtering device according to claim 10, wherein the filter BDcontains a second resin having a hydrophilic group.
 15. The filteringdevice according to claim 10, further comprising: a return flow pathcapable of returning the liquid to be purified to an upstream side of asecond reference filter from a downstream side of the second referencefilter, wherein the second reference filter consists of at least onekind of filter selected from the group consisting of the filter A andthe filter BD.
 16. The filtering device according to claim 1, furthercomprising: a tank arranged in series with the filter A on the flowpath.
 17. The filtering device according to claim 16, furthercomprising: a filter C which is arranged in series with the tank on anupstream side of the tank in the flow path and has a pore size equal toor greater than 20 nm.
 18. A purification device comprising: thefiltering device according to claim 1; and at least one distillerconnected to the inlet portion of the filtering device.
 19. Thepurification device according to claim 18, wherein the at least onedistiller includes a plurality of distillers connected in series.
 20. Amethod for manufacturing a chemical liquid that is for obtaining achemical liquid by purifying a liquid to be purified, the methodcomprising: a filtration step of purifying the liquid to be purified byusing the filtering device according to claim 1 so as to obtain achemical liquid.
 21. The method for manufacturing a chemical liquidaccording to claim 20, further comprising: a filter washing step ofwashing the filter A and the filter B before the filtration step. 22.The method for manufacturing a chemical liquid according to claim 20,further comprising: a device washing step of washing a liquid contactportion of the filtering device before the filtration step.